[MRCA] Australian WSA-38

[Ray Fantini]

I think my amazement is V1D being the second IF amplifier and the audio output amplifier at the same time. Been told such things were common in the old days or on regen receivers but just cant wrap my head around audio and RF going thru the same tube at the same time.

Ray F/KA3EKH


From: mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net] On Behalf Of Al Klase
Sent: Friday, May 04, 2018 11:58 AM
To: mrca at mailman.qth.net
Subject: Re: [MRCA] Australian WSA-38

Well, it reminds me of the BC-611 handi-talkie (Motorola).  Five tubes and a big slide switch that runs the length of the set to turn everything around.

[cid:image001.png at 01D3E3AB.294F9330]
Apologies for the fuzzy schematic.
Al
On 5/4/2018 10:37 AM, Ray Fantini wrote:
A friend just picked up an Australian WS-38 transceiver. Just for fun I went out and pulled the schematic on the set being I never saw one before and have to say that it may be the most complex and difficult design that I have ever come across for a small field radio. It has just five tubes and uses a couple tubes for different functions such as V1A as the mixer for the receiver and also as the modulator for the transmitter, V1B is the oscillator in both receive and transmit has its plate tied to V1A, V1C is the first IF amplifier and that along with the RF power amplifier V2A are the only two tubes not doing double duty.  My favorite has to be V1D that's not only the second IF amplifier it's also the receiver audio amplifier and just for good measure serves as the microphone preamplifier in transmit.  These are not multipole tubes in one envelope but just regular pentodes that in the case of V1D are being an IF amplifier and audio amplifier at the same time.
The layout of the set is compact and it looks like it would be an bear to work on it along with the fact that unlike just about everything else in the world where each tube would be labeled V1 for the first tube, V2 for the second and so on they just use V1 A, B, C and D to reference the tubes with the only tube getting the honor of a new number being the PA tube referred to as V2.
Anyone who may have personal experience please let me know about working with and using this strange little radio.
A web page that has good pictures and a schematic of the set can be seen at:

https://www.pa3esy.nl/military/gb/army/ws38/html/ws38_set.html


Ray F/KA3EKH






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--

Al Klase - N3FRQ

Jersey City, NJ

http://www.skywaves.ar88.net/


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