SS-201

Dragon SS-201 User Manual

Modification Sheet

From German Radio Amateur Jochen Heilemann (DG2IAQ)

Dragon SS-201 Version 1.1

25 - 30 MHz AM/FM/SSB Handheld Transceiver, 4 - 6 Watts

Introduction

The beautiful handheld transceiver came with a very quiet and low modulation. The original FM deviation was only 1,5 kHz on mine ! With the FM deviation pot on maximum ! Normally you should have a maximum to 2,5 kHz for german cb transmissions or about 5 kHz for amateur radio use.

Even the modulation sound wasn’t good enough for me. I prefer a loud and clear modulation with a sound like the original voice. Also the receiver had to have a more higher sound for recognizing signals in a little loud environments. With more heights in it, I can better understand poor stations. But that’s your own prefer.

With this modification sheet I had enhanced the transmitting sound, the modulation loudness and the receiving sound. Only the fm modulation is still a little too dark for me. But I can’t find the fm lowpass filter, cause the fm part isn’t drawn in the circuit diagram. I only found it in the circuit diagram of the german version called ALBRECHT AE-201S. But the pcb is difficult at these parts. So with my mod and with original fm lowpass I get about 2,5 kHz deviation with much more microphone sensitivity.

You mustn’t shout anymore !!!

And with this I mean the original build-in microphone or a external one. You could use preamp mikes of course, which give even more amplification and loudness. But I would like the handheld to work properly with the build-in parts cause in some cases you don’t have a preamp mike beside you.

For my mods I only have the circuit diagram of DRAGON SS-201 from:

http://www.mods.dk/mod/other/ss201ed.pdf

and the circuit diagram of ALBRECHT AE-201S form:

http://www.albrecht-online.de/service/Amateurfunk/SS-201/

If someone has a better or more detailed one, maybe with the fm part or with a pcb layout please send it to me !

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Modification Sheet

From German Radio Amateur Jochen Heilemann (DG2IAQ)

Dragon SS-201 Version 1.1

25 - 30 MHz AM/FM/SSB Handheld Transceiver, 4 - 6 Watts

General

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Modification Sheet

From German Radio Amateur Jochen Heilemann (DG2IAQ)

Dragon SS-201 Version 1.1

25 - 30 MHz AM/FM/SSB Handheld Transceiver, 4 - 6 Watts

Transmitter

Position the rig like this. You have to do the changes on the back of the frontside of the rig.

Unsolder the 4 points of the metal plate and open it to the top or unsolder all and remove the metal plate.

For the RX mods we have to go to this area.

For the TX mods we have to go to this area.

I removed the electret mike an drilled the mic hole up to about 3 mm for better an natural sound input. The original 1 mm hole was to small for my opinion.

Change R472 to 10k –yes, the big one- (more af output after mic amp. IC412B)

Remove R444 (was parallel fm deviation pot RV401 and reduces the fm modulation)

Change C448 to 68p (the left, brown) Change R473 to 680k (the right, black) Gives a higher amplification to the mic amp and opens its lowpass-filter from 2.8 kHz up to 3.4 kHz). On mine I only changed C448 yet and let R473 on the original value of 470k. This works fine. If I think I must have more preamp gain I will change R473 later.

Change R483 to 10k (the black one) It’s the internal PTT-Pulldown resistor parallel to the internal electret mike. This is the reason why the internal mike is much gentle like a external one. External mikes mostly have PTT-resistors of approx. 4,7 – 10k. The internal was a 2,2k and reduces mic sensitivity dramatically.

You maybe also have to change the PTT-Pulldown resistor of a new external handmike to 10k for encreasing gain. Some mini-handmikes come also with only 2,2 – 3,3k.

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Modification Sheet

From German Radio Amateur Jochen Heilemann (DG2IAQ)

Dragon SS-201 Version 1.1

25 - 30 MHz AM/FM/SSB Handheld Transceiver, 4 - 6 Watts

After this mod I put the fm deviation pot VR401 to the maximum (I think it was clockwise to the edge, but I’m not sure. It also can be counter-clockwise.)

On my rig there was another capacitor parallel to

the electret mike and not shown in the circuit

diagram. I removed it and the modulation rised up significant !

Now I mounted all pcb’s and switch the rig on. I go on FM and send to a dummy load.

· Center clarifier

· Put a DC meter to this short pcb line

(= measure point) On receiving you should readout a voltage of about 1,68 V. The exactly voltage doesn’t matter, but the clarifier has to be in the middle position to get the correct receive voltage.

· Now transmit while recognizing the DC meter. Adjust RV403 for the same

voltage as in receiving mode. Change

between tx and rx a little bit until the difference is about max 0,2 V. This is a not critical tolerance.

Now your rig has the same transmit and receiving frequency and has no offset or leakage (..like some cheap ssb export radios in germany...). My SS-201 had a tx voltage of 2,15 V with a receive voltage of 1,68 V !!! Good DX I say with this good conditions, hi...

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