Siemens 745E 310 "Rainbow" communication receiver

Siemens 745E 310 "Rainbow" communication receiver

Post by J M Noedi » Tue, 24 Mar 1998 04:00:00

I don't know why I did it, the house is already filled up so one person
have too little space, but I used those dreadful large empty boxes in
the army, and 'everybody' talks about them....
Do you have any technical notes for Siemens 745E communication receiver?
I bought it at an auction in Oslo on saturday. I need some info, and the
dial friction gear does not function properly, and all buttons have been
replaced.
I do not need circuit diagrams, LA8AF promissed to send me some copies,
but any information is valuable, if you have some files informing about
the valves.
A fellow mentioned that some input circuits could be removed to improve
the sensitivity.
The receiver covers: 14-21kHz, 88-175kHz,
170kHz-....30MHz - in 12 ranges alltogether.
Hpe cul.
73
Jan-Martin


<msg sent using Free-Agent>

 
 
 

Siemens 745E 310 "Rainbow" communication receiver

Post by Sandy W5TV » Wed, 25 Mar 1998 04:00:00



> I don't know why I did it, the house is already filled up so one person
> have too little space, but I used those dreadful large empty boxes in
> the army, and 'everybody' talks about them....
> Do you have any technical notes for Siemens 745E communication receiver?
> I bought it at an auction in Oslo on saturday. I need some info, and the
> dial friction gear does not function properly, and all buttons have been
> replaced.
> I do not need circuit diagrams, LA8AF promissed to send me some copies,
> but any information is valuable, if you have some files informing about
> the valves.
> A fellow mentioned that some input circuits could be removed to improve
> the sensitivity.
> The receiver covers: 14-21kHz, 88-175kHz,
> 170kHz-....30MHz - in 12 ranges alltogether.
> Hpe cul.
> 73
> Jan-Martin


> <msg sent using Free-Agent>

If you don't get a reply on your side of the Atlantic, I may be able to
help you.
Sandy W5TVW

 
 
 

Siemens 745E 310 "Rainbow" communication receiver

Post by J M Noedi » Fri, 27 Mar 1998 04:00:00

On Tue, 24 Mar 1998 22:40:58 -0800, Sandy W5TVW



>> I don't know why I did it, the house is already filled up so one person
>> have too little space, but I used those dreadful large empty boxes in
>> the army, and 'everybody' talks about them....
>> Do you have any technical notes for Siemens 745E communication receiver?
>> I bought it at an auction in Oslo on saturday. I need some info, and the
>> dial friction gear does not function properly, and all buttons have been
>> replaced.
>> I do not need circuit diagrams, LA8AF promissed to send me some copies,
>> but any information is valuable, if you have some files informing about
>> the valves.
>> A fellow mentioned that some input circuits could be removed to improve
>> the sensitivity.
>> The receiver covers: 14-21kHz, 88-175kHz,
>> 170kHz-....30MHz - in 12 ranges alltogether.
>If you don't get a reply on your side of the Atlantic, I may be able to
>help you.
>Sandy W5TVW

Thanks for your reply, I was looking for any suggestions to improve it,
and I have not received such notes, but LA4OE sent me a complete
collection of circuit diagrams.
I may modify the AGC circuit using few 1N4148 such that RF gain is
always active, but indicator tube does not show RF gain setting. Some
timeconstant has to be added (see Drake 2-B) using 47k in series with
1uF, and 2M2 (in paralell with 1N4148) to RF gain.
I also wish to test an improved product detector. The CW detector is not
a product detector, it was made before ssb, but W5DA indicates a
possible way to improve this, 73 June 79, page 33 fig 3. The IF input to
this valve 8V1may also need 1:10 (?) attenuation - 560pF/5600pF
combinations of grid circuit capacitors.

wonder why Germans very seldom are seen on the english newsgroups, I
have tried to use some German groups, but they are usually very much
afraid of replying, one must write in German, while French and Dutch
amateurs frequently post comments to English newsgroups. Several Germans
post in English to the VHF/UHF/SHF newsreflectors I subscribe to.

73
Jan-Martin