Degen DE1103 ultimate motorized machine experiment,Radio Review

Buy it Now
pcs sample


The idea of ​​writing this article, shortly after my first commentaries published the next few months, has been modified. This time a lot of radio scanning site users to buy the radio, and started a lively discussion at the forum. At the same time, I have received many DE1103 user’s letter as well as their evaluation.

Degen DE1103 has a lot of good quality, in fact it can be expressed better. Radio began this faith has been with me from the first day. Time has proved the DE1103 is not only a good product, but also flawed.
The purpose of the article – a summary of our discussions and released to improve the the DE1103 performance friction machine experiments. Not too complex experiments, in your hands will be another “new” radio. Although the appearance that sets of the DE1103, but it has to get rid of a “pediatric disease”, to use the better, more convenient.
In order to facilitate the repeated test procedure, I try to strive to achieve the maximum feasible. The article detailed description of the modification. To accomplish this, the need to prepare some of your components and tools. Mount machine experiments, however, I recommend surgery fine operation, so those who do not understand technology or are not sure to do the following people, I advise to keep the existing radio state or this thing entrusted to experienced experts.
Necessary warning: do not assume the reader alone repeat the following experimental operation, due to the possible dangers and damage to the responsibility of the radio.

In understanding the article before you worry at start!

Degen DE1103 major shortcomings:

– Volume adjustment inconvenience.
– The noise of the PLL circuit and the instability of the human body sensor sensitivity.
– Fixed stepping frequency settings.
– Power consumption
– To contain the image channel receiver capability is not high (according to professional standards).
– High-frequency sensitivity decreased (in the short-wave band).

These defects so that the radio along with the passage of time gradually lost their own utility. DE1103 power consumption is above average, but can also be accepted. Even using the supplied 1300mA rechargeable battery that can last 15 hours. With the charging function is also one of its advantages. For those users who use a capacity of more than 2000mA rechargeable battery, you can further reduce the short battery life problems.

There are a few words about the rechargeable battery. As confirmed by the experienced users, the benefits of one of the the Degen license capacity 1300mA rechargeable battery provided with this package. These rechargeable batteries in the radio is working properly, the capacity of the manufacturers nominal capacity of close to.

Degen DE1103

Sources said that the purchase of radio rechargeable batteries supplied poor quality, the individual name of the “Delay 4WD trademarks. This battery is unreliable, and some can not be used from the first day of purchase.
Long-wave / medium wave band frequency step can not be set 9 KHz shortwave can not be set to 5 KHz, the tuner is very convenient. General can not be changed, and the rest only get used to it in the search and set up radio stations to pay attention to carefully observe the display shows the number of frequency.
The rest of the designers did not improve, we can try to change on its own.
From the beginning, I surprised my DE1103 use an external antenna to receive stability. Degen DE1103 shortwave band strong signal reception ability is far beyond what their competitors. I did not foresee was that, shortly after users complained that the radio will have signal overload phenomenon, even if only with a simple antenna into the antenna interface. At that time, these comments make me confused, but the negative comments have been continued to the present. The message is unpleasant, because the DE1103 is not the usual overload of stability so that I am determined to solve this problem for experienced users, to recommend the transformation range from the general level, in order to find the one that is both good and not expensive, at home or the road with the radio.

My rotting fish on the first start from scratch “as well as the manufacturers do not necessarily” inference has recently been fully confirmed. Open a new version of DE1103 forum friends I confirmed I guess. Degen have been improvements on the radio, but retains its appearance, such as 2004, I purchased this. The new version of model in about October 2004.
The new version of Degen DE1103 existence of the phenomenon of short-wave band strong signal overload. Unpleasant facts have to let me the DE1103 defects directory and a – use an external antenna overload.
The new DE1103 appearance has not changed, a closer examination reveals the new is just the front panel to paste the circle with the letter “CNR” stickers.

To make sure your radio is which version, you can open the FM band tuned to any one radio station to a diameter of 3.5 mm empty plug into the antenna interface.

Degen DE1103 

The new version of the radio when you insert an empty plug rod antenna in the FM band is always disconnected, so the FM station reception should be decreased or completely disappeared. To verify this phenomenon is best tuned to a weak signal FM units, or inserting the plug, probably due to the strong signal “leakage” of the interface contact capacitance did not notice this difference.

If you plug in the empty plug confirmed the existence of differences, that is the new version of the DE1103 – but also do not hurt. The remaining aspects (overload) in addition to an external antenna, the new version than earlier versions of the difference. In order to correct this defect, return to the more efficient external antenna circuit state, you need to add two capacitors.
Friction machine steps are divided into several chapters, each part connected to the independent work of conversion. Some modification with the recommended characteristics, they must do in order to amend manufacturers mistakes, I suggest that modified them. The chapter name will be with the “recommended” text to give marked. The rest of the modifications to improve the effect is not very obvious, by the user in line with the desire to tap the maximum potential “. However, the rewards of your labor will bring a more modern, more convenient effect for your listening.

A. Dismantling

       The first part is the first intention of dismantling their own radio users. The following is a detailed description of the dismantling DE1103. Has been dismantling the radio immediately forward to the next chapter.

       Panel down to the radio on the table, remove the battery from the battery compartment. Tighten the seven screws and the panel after the case was marked by the arrow. Do not forget the screws in the battery compartment. Do not twist for fixed rod antenna that screws.

Degen DE1103

Along the fuselage surrounding careful sanction from the Central seams open before the latter part of the chassis, starting with the bottom and then along both sides.

Degen DE1103

The upper half of the chassis combined with relatively tight, use a little force in order to completely separate. Part of the chassis itself and the third part together.

Degen DE1103

Degen DE1103

In the latter part of the chassis circuit board wiring socket, remove the white flat cable, pinch flat cable connector behind the site, and slowly pull out.

Degen DE1103

Unplug the wire from the Jog to adjust the wheel from the wiring base.

Degen DE1103

The two halves chassis speaker wire connections, and welding under the wire from the speaker contacts.

Degen DE1103

Radio, the front panel (with display and buttons) placed outside, can be seen due to the friction machine touch the printed circuit.

Degen DE1103

In the circuit board connected to the welding foot welding open the ferrite antenna lead and whip antenna wire. In order to avoid assembly errors, recommends starting with the first draw down the manufacturers of ferrite antenna wires.

Degen DE1103

Opened to the tuning Shuttle round orange wire in the circuit board solder.

Unscrew the small screw from within the casing back cover fastening board, lift the circuit board, starting with the left direction (with an external antenna, headphones and an external power jack).

Degen DE1103

If you lift the board encountered the obstacles of the ferrite antenna, you can tighten the fasteners, then the right side under the mast antenna to move up a little.

Degen DE1103

Finally, the right part of the circuit board from the casing back cover (installed Jog tuning wheel).

Two. Modification of an external antenna connector (* recommended – limited to the new version)

Prepare two miniature ceramic capacitor with lead 33 … 150 nF (0,033 – 0,15 μF).

A. Such as shown in the photo location, cut there two printed conductors. Remove the capacitor in the circuit С1.

Degen DE1103

Two.Capacitance in the circuit board solder on there, the wires of the circuit board edge two adjacent conductors, such as shown in the photo. (Note: the Перемычка – jumper)

Degen DE1103

Now connect the external antenna when the whip antenna preamplifier will be disconnected, the radio is no longer overload.

Three. Modified frequency synthesizer (recommended)

Prepare two capacity of 15 nF (0,015 μF) ceramic capacitor, the best of SMD (for surface mounting).

A. 15 nF capacitor to replace capacitor С404 (next to the frequency synthesizer IC).

Degen DE1103

Degen DE1103

Two.Polished clean and a short printed conductors, leading to the two oscillators to the bottom of the shield back cover (see photo), and then welding 15 nF capacitor between the ground and the circuit board.

Degen DE1103

Degen DE1103

After complete conversion, using the Jog tuning will not be issued to the original noise and to Gurkha cracking sound. No noise in the shortwave tuning.
However, in order to rid itself of the PLL circuit noise and self-excited only by relying on the shield (see the “mask”).

Four. Modified long wave – medium – short-wave unit input filter

This will improve the sensitivity of the radio above 15 MHz frequency. Progressive “blocking” the original input filter is higher than 12 MHz. For this reason, the sensitivity of the shortwave band high-frequency region will produce 3-4 times the decline. I infer that according to listen to the experience in the use, to receive less than 20MHz frequency signal can eliminate this defect. So when using the whip antenna, the preamplifier circuit the DE1103 sensitivity to achieve the very high end.
Modification of the input filter is my opinion, the expansion plan, the first recommended to use an external antenna to receive short-wave high-frequency band of lovers, as well as those distressed DE1103 sensitivity decline user. Can significantly improve the first IF to curb the ability to image channel (see measurements). In addition, the modified filter can improve the sensitivity of the frequency band above 30MHz, concrete will be talked about in the back.

Prepare miniature ceramic capacitors:
5,6 pF, – 1,
15pF – 1,
22pF – 1 (preferably SMD)
130pF – 2 (preferably SMD).
Lead inductance 330nH (0,33 μH) small high-frequency choke coil 2.

A. According to the piece shown in position to cut the signal circuit board printed circuit board, line polished clean and tin-plate.

Degen DE1103

2, with the the 330nH high-frequency choke coil to replace the inductor L105 (upper part of photo), and second cut line on the location of welding the 330nH high-frequency choke coil. Parallel this inductance and then welded on a 15pF capacitor (in the photo is not shown).

Degen DE1103

3, replaced with 22pF capacitance С132 130 pF exchange С135. A 5,6 pF capacitance in the filter circuit, as shown in the photo on the new location, there is a 130pF capacitor (the lower part of photo).

Degen DE1103

Because of the lack of a capacity of 130pF of capacitance, each time I had to 130pF of capacitance from the total capacity of capacitors used in parallel (see photo section) replacement.

Correct filters to the extreme:

Compare the previous amplitude-frequency characteristics of …

Degen DE1103

Modified to:

Degen DE1103

Instrument Grid: the level of 10MHz, vertical 10dB.

Detailed features of the new filter will be talked about in the back, in the measurement of the articles.

V. Change the volume control and SSB mode frequency trimming

Modified to control the volume using single sideband fine-tuning knob FINE, fine-tuning in the SSB mode will be Jog tuning round after pressing the VOL button.

Preparation: a low-power impedance 3,3 KΩ resistor (3,0 KΩ or 3,6 KΩ), with insulated thin connecting wire (Model KMZK, etc.).

A. The front of the board as shown in the photo location, cut the printed conductor.

Degen DE1103

Degen DE1103

Two.The circuit board on the back of the left lead length of 75mm wire to connect a resistor R706; wire the other end from the Wang Youce connection, such as the photo below.

Degen DE1103

Degen DE1103

3.Remove the circuit resistor R514 (in the “VOL” signs welding feet lower left).

Degen DE1103

Note: убрать, – removed.

Degen DE1103

4.Length of 90mm wire to connect the fine-tuning knob FINE lower output, as shown in the photo (“А”) connection, the fine-tuning knob FINE-ended output after 3,0-3,6 KΩ resistance welding feet “VOL” is connected (connection “B”)in this scenario, the resistor placed in the wire break in the distance between the two wires, 15mm and 65mm.

Degen DE1103

Another connection method is much simpler. Ended output welding directly on the fine-tuning knob to add resistance on the other end through the length of the wire 70 … 75mm and point “VOL” to connect.

Degen DE1103

Degen DE1103

5, with the grinding stick with Quick Adhesive wire fixed on the circuit board.

Degen DE1103

Now with the single-sideband fine-tuning knob FINE is more accustomed to adjust the volume, the SSB mode fine-tune the third local oscillator can be used Jog tuning wheel by pressing the VOL button (refer to manufacturers volume adjustment). Digital volume level is displayed on the display of the modified and the third local oscillator the relative solution to match the resonant frequency.

I modified to use the radio, the following relationship with the tuning the third local oscillator (measured to the step tuning mode band at several points):

    Volume level VOL            The detune relatively IF receiver
        00                                           – 1860
        10                                           – 1285
        20                                           – 717
        30                                           – 150
        40                                           + 470
        50                                           + 1168
        60                                           + 1562
        63                                           + 1622

Each radio tuning band edge values ​​may be different from the above example, the total harmonization of the band in 3,2 … 3,5 KHz, range within. 64 to adjust the level of the average step tuning is about 50Hz, but the non-linear curve control is not always effective, tuned near the band edge changes from 60Hz to 30Hz. The center tuning in the region of 30 … 34 level, the specific decision to the third local oscillator parameters of each radio.
Third local oscillator frequency stability is very good – in the circuit with electronic “expansion” of the varactor diode resonator.
After modification, you can use the timing function according to the precise frequency of the preset to receive SSB radio. Remember? Factory way to set the time and the receiver to open the radio in the last tuned frequency (or memory cell) can also preset the volume and 60 minutes time. SSB receiver in the case of this automatic boot could go wrong, there is damage frequency of the possibility that pre-FINE precise tuning of the fine-tuning knob set.

Now, use the “digital” way to control the third local oscillator and save this parameter to set the clock store, you can ensure the stability of the tuning and receiving SSB signals according to the preset clock. Only need to pre-record, store the current level of detune (VOLХХ) value; Similarly, setting the clock, the volume level alone and the power-frequency (or memory unit) to separate. The modified regular boot volume after the decision by the state of the fine-tuning knob FINE, it needs to be transferred to the voice of the size of a comfortable position in advance. The rest of the timer function to retain the former. Using this precise time and frequency automatically turn on the radio, radio enthusiasts and single sideband service listener is valuable. The existing the DE1103 two independent alarm clock function only to expand the “timing” the possibility of receiving the SSB.
On the other hand, modification in the radio search to retain a voice in the speaker (search mode). Manufacturers muted when the station search.

Six. To change the automatic gain adjustment constant time

Automatic gain system is a bit slow in my opinion. If this involves only the long wave – medium – short-wave band, do not use automatic gain system in the FM band. Radio when the receive signal size of the level of the rapidly changing somewhat “late” to restore the gain a little stagnation. This is far from the critical state can be completely eliminated, or even most users are not aware of the automatic gain system inertia. Experienced radio enthusiasts, more vividly listening to the tone behind the “live”, they can be easily modified automatic gain adjustment of the DE1103.

Preparation: the capacity of a small size (height does not exceed 10mm) electrolytic capacitors 1μF.
A. Remove the circuit capacity of 10μF capacitor C206 with the new alternative, pay attention to the polarity connected.

Degen DE1103


Automatic gain adjustment has become “much faster”, you can receive dynamic signals. (S-meter band) signal reception level indicator readings will also receive a smaller inertia.

VII. Shield (recommended)

If you want the DE1103 a better performance of the play, should be the signal circuit board on the back of the shield. After implementing the above modifications, the shield will bring the best reception quality.

But before the start, I should explain, for even at the end on the DE1103 shielding. In order to correctly use the “power method” This is necessary, that is to the greatest degree of shielding effectiveness.

Radio, two small pieces of the lot is shielded critical point. This place is furnished with a frequency synthesizer integrated circuit and the first intermediate frequency of quartz filter. Manpower close to the location of the synthesizer, the PLL IC on the shield would rule out the interference caused by self-excited because the circuit. Similarly, we can greatly reduce the roar of the frequency synthesizer output signal. DE1103 this manufacturer defects significantly affect the high-quality reception of AM and SSB signals.

Most users modified the recommended shielding, have clearly taken note of the radio on the shortwave band performance improvement. I also can not understand until now the factory technicians travel: It is well known in circuit board layout of the resonator and PLL loop filter to shield the necessity, which has made it clear description of the frequency synthesizer IC manufacturers . It is precisely the sensitivity of the causes of high impedance output.

Is worth noting that, to this new version of Radio synthesizer “roar” than my first radio in extent has been greatly decreases. Received detailed comments from other new DE1103 user. Frequency synthesizer, “Coo na” signal in the new series is so clear, as in the use of monitoring equipment, also receiving the SSB radio broadcast. But no matter how the layout of the location of the synthesizer IC shielded short. When manpower to close the circuit board, the circuit to generate self-excited in the new version of the radio is still there.

Shield mounted on a quartz filter and the back of fine-tuning to contain the image channel increase 6dB for a second IF (+900 of KHz, the relative radio tuned frequency). If you take into account this parameter (-42dB) to high initial values, then add the shield is obvious!

I hope do shield the radio input section. DE1103 high sensitivity and a negative role. Board input part of the circuit to be subjected to the adjacent power interference and human inductive influence. It should be said, the DE1103 input part of the antenna effect and level GRUNDIG YB400 the same has not been fully play out. But no matter how to install additional shielding is useful.

Experiments are two ways to shield the DE1103. The first is described in the article. Recently, the forum also appeared in the second method: the overall shield in the back of the circuit board production.

I recommended to the reader is a program of the critical point of partial shielding circuit board, a not too complex. Produced by normal wires connected to each other, the installation of a single shield, to multiple connect the shield to compensate for overall shield capacitance to reduce the probability of contact between the high-frequency nodes located in the circuit.

Produced in accordance with the following sketch, install shielding to the specified location.

– Brass, copper or tin-plated thin iron (steel), thickness of 0,1 to 0,35 mm
– A ruler
– Scissors
– A small flat nose pliers
– Paper adhesive tape
A. Sketch cut thin sheet iron shield (view upward, the unit mm).

Degen DE1103

As fixed feet from the edge of 2,5-3,0 mm from cut depth of 3mm.

Degen DE1103

Two.Folded down for the fixed shield feet relative to the sketch plane position. Each of these feet height should be about 2,5 mm. If the foot is too high, it does not matter – it is easy to bend to shorten the installation pay attention to adjust the height of shielding from the circuit board.
Shield inside surface of all the glue paper adhesive tape.

Degen DE1103

3, the circuit board shielding the fixed point polished clean and tin-plate.

Degen DE1103

Degen DE1103

4, the shielding installed close to the circuit board and solder them as shown in the photo.

Degen DE1103

Degen DE1103

Degen DE1103

Eight. Jog tuning wheel
Some DE1103 user to reflect the shorter life span of round mechanical tuning Shuttle. Formally as follows: hand slow knob tuning wheel will suddenly “skip” a few steps, on the fall in the wrong direction tuning and frequency settings wrong. No accurate information about the defects of the time. Some cases Jog tuning wheel shortly after the damage, while others (including this author) spent a long time no problems have arisen.

It should be noted, that the manufacturers have taken note of the problem and quickly made adjustments to carry out random checks of the reliability of the tuning components. Improved, even if the super-strength (fast rotating circle around a total of 5 million), Jog tuning wheel can also maintain its status.

Now, if using the Jog tuning in case a problem occurs, it is recommended to open the small wheel and cleaning its internal. Machine filled with pure silicone lubricant Jog tuning wheel can continue to use. But it is unclear after the repair can play long. The process of dismantling, cleaning, original tuning Shuttle wheel in the forum has been discussed many times.

The other solution is to use the new to replace it.

Nine. Increase the charge current

The the DE1103 advantages of one built-in charging device. You can also set the charging time, which is more than only a simple charge. Unfortunately, the designers did not take into account the automatic power-off after the battery is fully. Heard the new radio will achieve this. By a simple calculation of battery capacity and charge current manually select the charging time, this can keep rechargeable batteries in the state, to extend its life.

Measuring the charging current of a few radio results from 80 to 115mA. Manual annotation is 100mA.

DE1103 rechargeable battery provided with the packaging capacity of 1300mA. So, charging the device inside the machine is fully charged 18 hours. Charge timer is set to 1 hour intervals to a maximum duration of 23 hours. In this way, the maximum battery capacity can be fully charged 1600mA / h It takes almost a day and night time. Not only time consuming but also for the larger capacity battery is fully charged. Some radio users to use the capacity of more than 2000mA / h rechargeable battery, in order to fully they require two cycles, the total charge time to take up a half day and night!

More than twice the charge current can be increased by a simple modification. Corresponding to shorten the charging time, charging time (23 hours), the largest rechargeable battery capacity of 3200mA / h.

Found in the back of the circuit board next to the battery spring the two resistors (in the photo they are labeled 1 and 2).

Degen DE1103

Remove from the circuit resistance № 2, resistance № 1 with a wire connected.

Modified my radio started charging current increases from 85 to 205mA. End-of-charge current down to 180mA. To change the charging circuit, I suggest using only high-quality rechargeable batteries.

Use capacity is unknown or ordinary rechargeable batteries, used to be “fast” charge repeatedly charging, then the resistance № 1 intact (not connected). When the charging current is only doubled (occasionally up to 155mA), but reduces the risk of individual battery to short circuit caused by the transistor Q26 output is very damaged (a very rare phenomenon).

Modified, it is best to measure the charge current in order to estimate the charging time.
Retain DE1103 old “slow” charge mode, even if the wrong set charging time also do not have to worry about overcharge.

Ten. Open to receive lower than 100KHz higher than 30MHz band

Previously published online message on DE1103 receiving less than 100KHz possibility. In our forum discussions in this regard (and also found extended to receive higher than 30MHz – special thanks to luv). The founder of the radio for their own births planted a hidden talent to find open its keys like to thank the rapid spread of the Internet world. The good news is that this modification only need to operate the buttons on the radio, without having to open it. The DE1103 open to receive the band itself is very interesting results brought joy to speculation. So that the the DE1103 extended to the broad-brimmed with a radio receiver.

The following are extended to receive lower than 100KHz band description:

A. Turn on the radio (2-1-9-5-1 – BAND + “), press the number keys to enter the tuning frequency to 21951KHz.
Two. Press two keys: “BAND-” and “BAND +” until well into the downward frequency scanning.
3. Wait until the current scan frequency close to the bottom edge of the 100KHz (this time). Note that in this time do not touch the tuning Shuttle wheel – otherwise it will cause the scan was forced to terminate, the process had to be repeated. When the scan to reach the bottom edge of the 100KHz crossed it, pay attention to careful. Need to press any key or turn the Jog wheel tuning stop scanning. Display a frequency lower than 100KHz instructions divided into three sections, for example: 50KHz

Degen DE1103

4.Record or a lower than 100KHz frequency to the storage unit: Press and hold button “STORE, use the Jog tuning wheel to select the storage unit number, release and then press a” STORE, “. Best to use the beginning of the storage unit – to facilitate future use.

Note: The tuner can only use the Jog wheel to select the stored frequency.

Open the higher than 30MHz, please continue with the following steps:

A. Turn on the radio (2-1-9-5-1 – BAND + “), press the number keys to enter the tuning frequency to 21951KHz.
Two. Press two keys: “BAND-” and “BAND +” until well into the downward frequency scanning.
3. Press any key to stop scanning, then press and hold BAND + “key until the beginning of the upward frequency sweep.
4. Wait until the frequencies above 29950KHz, stop scanning, record the stop frequency to a memory cell.
5 Press the “M / F” key to evoke the memory cell frequency and repeatedly pressing this key to enter manual tuning. The display will show the frequency of the previously stored display the right part of the tag “MEM” becomes “VOL”.
6. Press and hold button “BAND” to start up the frequency scan. Scan across the the boundary 30MHz (readings on the display in the form of the Б0000, the first letter of the Russian letters Б reversed. Note: When the display reading between the the “Б0001 and Б0009” (30.001-30.009MHz ) need to stop scanning.

Degen DE1103

With Jog tuning can tune the high-end frequency. Key in the specified interval to be able to successfully stop the scan, or Jog tuning into the higher than “Б0010 band. If you do not stop scanning, then immediately after “Б0010” (30.010MHz) radio into the FM band. The process had to re-start from 5.

7. Stop scanning, with Shuttle tuning wheel tuning any higher than the frequency of Б0010 “and store it to facilitate the future use of the storage unit.

Your DE1103 can now receive less than 100KHz and higher than the frequency of 30MHz. But tuning these frequencies different from the general method of DE1103. From the “open” band frequency can not be directly using the key input, you can not use the band conversion key “BAND-BAND +” entered a new band. Can only evoke the previously recorded in the storage unit in any one of the “Open” below 100KHz or higher than 30.010 MHz, the frequency, then press the “M / F” key to enter manual tuning mode.

Knob tuning wheel or start the scan can be set to the frequency you want, but if the storage unit difference between the starting end of the frequency and tuning frequency, you have to spend a little time to re-tuning. It is therefore recommended that the ladder distribution of the “loop” frequency (for example Б0000, Б1000, Б2000 ……), to facilitate the preparation of the storage unit of the radio, fast tuning.
The DE1103 need do not need to receive the “open” frequency? A DE1103 user to decide. High 30 MHz frequency, near the residential area can listen to the civilian work in the narrow-band band radio use a little detune clearly this kind of amplitude modulation frequency with AM reception. Some individual districts save in the 33-38MHz range “national – economy” broadcast, and also using narrowband frequency bands.

Less than 100KHz, actually listen to only one obvious existence of the “frequency – 66, (6) KHz standard time radio signal. This needs to be connected to an external antenna for the radio.
Occasionally found, after the above “open” process, receiving less than the frequency of 100KHz to 1710KHz can choose to use the antenna – the internal magnetic bar or rod antenna.
Start manufacturers way to tune below 1710 KHz, ferrite antenna is always connected to the rod antenna at this time is to disconnect. This was retained in the “open” into the DE1103, use ordinary way tuning is less than 1710KHz (direct input frequency or band conversion button). If it is lower than 100KHz band into the open by the “low-end frequency and then evoke the memory cell M / F” key to move to the manual tuning mode, then the radio will use the whip antenna to receive. Continue to use more high-end frequency tuning Shuttle rod antenna receiver will be retained. Return to the ferrite antenna receiver is first tuned below 1710KHz frequency in the normal way – converted by digital selective or band button.
I found the old version of DE1103 use ferrite antenna receiver (frequency less than 1710KHz) at any given time can be connected to an external antenna connector, converted to an external antenna to receive. The same modified version DE1103 antenna connector. Without modifications to the original version radio is impossible to use an external antenna to receive below 1710KHz signal. Only after the above steps to open a version lower than 100KHz radio will appear to the possibility of using the whip antenna to replace the ferrite antenna, only then we can use an external antenna to receive signals, connected to an external antenna connector at the same time using the whip antenna. Seems connected to the steps of the long wave / medium wave external antenna on the practical application of more complex, let alone use without modification of the original version DE1103.

Xi. Test results

The last part is the radio of the parametric test results and the necessary descriptive information.

Use two radios were tested:
– The DEGEN the DE1103 original number: AI017885 – new version
– The DEGEN the DE1103 original number: AI014128 – Previous
There are two DE1103 only through the instrument simple test performance, the results are also included.

Very close to the performance of modified two versions:

Degen DE1103

1.SSB receiver sensitivity in the way

11dB for the AM band is better than the above value, that is 3.5 times. This depends on any point stored in the radio band. Sensitivity in the 5MHz frequency in the single-sideband mode for 0,3 μV.
The table in the beginning of the lack of the sensitivity of the new version of the radio machine automatically switches to the ferrite antenna tuning lower than 1710KHz frequency. Old version of DE1103 external antenna connector all the SW, has been connected.
The new version of the original DE1103 external antenna connector at the sensitivity is equal to the sensitivity of the rod antenna (previously explained, the rod antenna and external antenna in the joints conversion, the signal from the antenna is always to enter the high-frequency amplifier input). For earlier versions, the new DE1103 amplifier sensitivity improved a little laboratory values​​, because earlier versions of the amplifier will stop working when connected to the external antenna.

Preamplifier can use an external antenna, the new version of DE1103 what “benefits” we already know. The sensitivity of the new version of the original radio only refers to the ability when it uses the whip antenna to receive the previous version of DE1103 sensitivity manufacturers from the beginning of the implementation of the value of using an external antenna.
It can be seen from the table, the modified input filter to improve the sensitivity is higher than 20MHz band. Also, in the first intermediate frequency of the SW, to contain the image channel capacity was increased to 50-70dB. The DE1103 mirrored reception range is located in the FM band (according to the first local oscillator resonance) and the former Soviet Union ultrashort wave band (resonance) by the second local oscillator. So, I think to use an external antenna to receive SW to minimize interference from ultra-short wave transmitting station.

Degen DE1103

New input filter inhomogeneity does not exceed 5dB bands overflow the upper boundary is 37 MHz, can be seen as “open” than 30MHz receiver. The DE1103 modified “open” higher than 30MHz sensitivity is maintained at a high level.

Degen DE1103

Sensitivity in the AM mode(SINAD 10dB), μV, In the antenna joints.

  Frequency, MHz                DE1103-RS (RadioScaner)
            31                        1,4
            32                        1,6
            33                        1,8
            34                        1,8
            35                        1,8
            36                        1,2
            37                        1,0

This limit to receive the radio frequency is 37.100MHz. No matter how high it will overflow synthesizer boundary. Depends on the stability of each radio (tuning and ГУН of parameters) are generally open to receive the boundary is located 33 … 38MHz range. Control the synthesizer frequency to save 39.999MHz (Б9999).

The measurement signal level indication (by increasing the degree of the receiving frequency of 10.000MHz)

       -92 DBm, (5,5 μV)
       -87 DBm (10 μV)
       -81 DBm (20μV)
       -75 DBm (40μV)

Degen DE1103 

Indicator level adjacent segment the difference between this measured radio-7dB, which is an average of 6dB or press S to scale. My radio full level indicator scale almost coincides with the receiving level of S9, so the reception level indicator scale can be expressed as the following forms:

– Lock the dynamic range: a new version of the old and modified DE1103 at the antenna connector 79 … 80dB. The dynamic range of measurement can not be due to the lack of necessary equipment. From the BDR numerical evaluation of the stability of the intermodulation level numerical results for the 65-70dB.

– The containment of the second IF competing channel to receive: (signal 900KHz above the tuning frequency), AM and SW, the original way is-42dB, modified for -45 …-48dB.

– Attenuator: the DE1103 only effective in the LW / MW / SW,. Measuring the attenuation of the results of 14-17dB, concrete determined by each radio and receiver frequency.

Measuring the adjacent channel selectivity DE1103 AM reception mode to obtain very good results.

Filter band       Curb adjacent channel receiver  –5 KHz, dB       Curb adjacent channel receiver +5 KHz, dB

Broadband            -19            -17
Narrowband           -51            -51

Between adjacent channel the standard 9KHz frequency selective test results are as follows:

Filter band    Curb adjacent channel receiver –9KHz,dB       Curb adjacent channel receiver +9 KHz, dB

Broadband                       -60                           -56
Narrowband                     -61                           -63

Measurement of all the AM channel frequency band, according to the level – 3dB/- 60dB/- 70dB

Filter band by band,KHz (- 3dB)   By band,KHz (- 60dB)    By band,KHz (- 70dB)

Broadband    -3,6…+3,1    -9,5…+9,1    -28…+22
Narrowband    -2,2…+2,6    -7,5…+8,0    -18…+18

Description: The radio filter in the above selective list of “standard” indicators, generally take a basic measurement of the filter amplitude-frequency characteristics. In this case, test DE1103 like a “black box” the same from antenna input end to the S-meter wave data to obtain high quality output parameter. The above level differences and not in the center frequency receiver variable frequency carrier relative level match.

Total direct channel selectivity, and contains its own filter amplitude-frequency characteristics of the first and second intermediate frequency. Almost rule out a weak signal measurement on the automatic gain system, we can say that the characteristics of the filter is through the main signal. Actually more important is the “real” performance, the radio does not always match the performance of the radio manual.
The results obtained in the analysis of the table to help DE1103 filter to make the best choice in practice. Load broadcasting SW shortwave bands adjacent to radio each other the 5KHz interval band to receive the transfer switch must remain in a narrowband filter state. Long wave and medium wave segment 9KHz frequency interval step can be converted to “broadband” band on the radio. Filters selective conditions so that different frequencies almost no difference.

In the long wave and medium wave segment to open the meaning of the “narrowband” filters only for occasional public or a constant high-frequency interference. Of course, in the LW and MW band signal reception quality depends on the choice of the filter, the narrow band receiver obvious limitation of listening to the radio band frequencies. Again indicate the DE1103 has made a successful conversion by the band parameters.

Automatic gain adjustment system measured as 43dB.

       Noting that the system can be a good choice to start work time, and the effect is significant. When the input useful signal level of -90 dB (7μV) stable amplitude of the output signal is passed, the high frequency output signal amplitude changes of only 1.5 times (1.2dB) can improve the signal at the input level to-47dBm (1mV) . If you continue to increase the useful signal level of the input, then the radio will not be able to control the circuit, when the level is about 30dBm (7mV) amplifier stage is close to saturation, began to distortion.
Summary of measured satisfaction (comfort) and listen to the band the useful signal level about 60dB – for this level radio is a very good result!

Mount the machine does not touch the FM reception band, the original performance reserves has not changed.

FM-band receiver sensitivity at the input end of the rod antenna, μV

Frequency,MHz         SINAD 12dB         SINAD 20dB
     76,00                         0,8                         1,0
     99,50                         0,5                         0,7
     108,00                       0,6                         0,8

Below the standard IF 10,7 MHz in DE1103 LO frequency of the FM band. Mirror band receiver located in the former Soviet Union FM frequency band (and now many cities are still using). Here encountered three meters of the television sound channels (83,75 MHz). Interference results from the high-power transmitting station is: +21,4 MHz frequency in the vicinity of the radio relative to their broadcast frequency can listen to these bands.

Three. To contain the first IF image channel in different sections of the FM band (measuring point connected to the rod antenna):

Receiving frequency (image channel frequency) KHz suppress the image channel, dB
          87,4 (66,0)                             70
          96,4 (75,0)                             60
          101,4 (80,0)                           48
          108,0 (86,6)                           45

It can be seen from the table, the received image channel in the former Soviet Union “FM band attenuation more than 60dB.If the ultra-short wave transmitter is not nearby, generally this is enough. Worry about only when the radio tuned to 105,15 MHz (105,15-21,4 = 83,75 MHz) frequency evocative “fleeing” the possibility of three audio channels of TV. Moscow during the day and listen to FM radio 105.2MHz this interference.3, the end – on the battery indicator

3, the end – on the battery indicator

Degen DE1103 4,0 V <battery U <4,3 V (battery indicator flashes.)

Degen DE1103 4,3 V <battery U <4,6 V

20110626044958312 4,6 V <battery U <4,9 V

Degen DE1103

Battery U> 4,9 V 

When the battery voltage and then down to 4 volts, the radio will automatically shut down.

Degen DE1103

After which only radio in the battery voltage above 4.2 volts before they can boot.

4 In other news:

Here to answer some of the problems of the forum on the DE1103.

(How) “Open” FM band is lower than 76MHz is still unclear.

The difference between the old and new. I added that the new version of “the DE1103 circuit board there are three significant differences in contrast to earlier versions with the naked eye can be noticed – there is a new fine-tuning capacitor (photo on the mark 1) and jumper (mark 2).

Degen DE1103

The new blue wire – ferrite antenna amplifier automatic gain adjustment system Extension. In previous versions did not.

Degen DE1103

The use of the jumper (detachable connection) between the second IF 450KHz input filter and the second mixer signal line interrupt. In other words, this is the last IF AM-SSB-band line input. Remove the jumper to bring the AM-the SSB receiver interrupt. Why have the new version of the jumper I do not know. Most of the manufacturers for easy adjustment.

The new version to increase the tuning capacitor is allowed to set in the SW band tuning step to adjust its accuracy. The 1KHz this difference is located in between (quartz) LO two variable frequency 55.395MHz and 55.396MHz. An earlier version of the radio components, rely on the mobile frequency between the fixed capacitor to determine. Installation errors due to the discrete parameters of the second local oscillator circuit, the odd tuning frequency values ​​can be up to + /-200Hz

In short, the new DE1103 proved to be the Model 1103 is very good successor. Are not an engineer at the antenna connector on the line this regrettable error, then the rest for the radio, the benefits of: receiving SSB band clearly and precisely set the local oscillator, long wave and medium wave receiver attached to the automatic gain adjustment systems.

Connected to the possibility of the S-meter wave external pointer. AM-of SSB mode is proportional to the IF IC output voltage and the received signal level. This is connected to capacitor C206 (see modification of the conclusions reached by the automatic gain adjustment system article). Voltage changes from the lack of signal 50μV maximum signal 550μV into the processor – the signal level to determine a station is found and stop scanning on the display. This voltage can be used for external purposes, but must use a high-impedance input line.
The DE1103 acoustic characteristics of the performance of high-frequency distortion. I did not touch in this regard for several reasons. First, the original speaker playback quality and low-frequency amplifier circuit I think it is acceptable. Medium-volume sound (compared to the shape of the radio size and level), the speaker output signal distortion at high volume. DE1103 obvious sense of sound in large rooms. Shell size, speaker diameter and increase the current demand to limit the sound performance of DE1103.

Users from the forum to argue there is no boundary on the map the performance of the sound spectrum. Some bias in the low frequency components, while others opposed to “remove the high frequency. In any case, this is independent of personal problems, rely on the correction of high-frequency line to please the ears of all the practices and meaningless. In my view, the FM sound change-over switch NEWS-MUSIC “fully meet the demand. Radio line out feature to bring the possibility of using external speakers to improve sound quality. At the same time, there is no foreseeable research in the area radio speaker head placed several internal sound school program. Here is a testing ground for enthusiastic user and inventor, they can try to realize their aspirations to improve the sound quality of DE1103.

At this point, the the DEGEN the DE1103 radio and modified end of the experiment. Hopefully, this article can help some of the DE1103 users enjoy a better reception.

Buy it Now
pcs sample


You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *