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The Braun SE400 all mode 144MHz classic rig .

After many years resting on a shelf brought back to life. In 1975 this was a very expensive  German hand made 2m all mode rig in Gründig style.  My IC706  is temporary out of operation to investigate a "bad" modulation problem. So why not using the good old SE400. Inspired by an article of PA0FRI.
Once considered as the best 2m rig on the marked, made with the best ,expensive.. electronic parts , an oldtimer but high receiving sensitive without birdies and digital noise, a pleasure to listen on a radio where the little noise you hear is actually "from the antenna"
The VFO is 4-6 MHz an unique system build around a color television delay line  a with phase wheel tuning 1kHz resolution of the 4-6 MHz freq counter display . Missing CAT connection 
This type of VFO should not have a very low side-band noise so this rig wil not rank high in the Sherwood RX listing. I did not notice problems yet. Testing local gave a relative small signal at high level. We have to wait what it does when the real strong "contest terror" signals are on the band again...  

Major trouble , bad relais contacts  RL2 the 9V and 14V (13.5) TX RX switching failed. After thorough cleaning that was okay.

Using a md 500Z "Fortune" CB mike, my modulation was reported as very! good for a change!

Had to keep the mike gain below the clipping level the gain of the 3 transistor microphone amplifier is high. 

done some modifications in the past :

1.CW a receive -600Hz offset  

2. KOX  key operated T/R with adjustable hang time

3. The REC 5-pole DIN modified for digi modes i.e. packet radio

Now some extra minor modifications:

PTT out relay contact to an RCA. PTT external in was switching directly the 2 relais 14v /80mA with an opto-coupler and IRF510 PTT-on is now reduced to 9V by 1.6mA for PC control. FT8 worked nice frequency resolution only 1kHz but stable delayline phase wheel tuned VFO. Drawback no CAT control  

 




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