[MRCA] British EF-39 tube

[Christopher Bowne]

The Pye designed WS19 MKII I have also suffered from being very “hot” RF gain wise.  Made it very hard to copy CW and SSB signals because the high signal levels would swamp the BFO.  I added my own unauthorized field change RF gain pot, using if I recall correctlyone from a  Commad set receiver remote control box that I cannibalized.  The only place to put it on the WS19 front panel was in the upper right hand corner.  The fix worked (and still works) very well.  A few years later I saw my first WS19 MK III with its added RF gain pot which was part of the MKIII upgrade, installed right where I put my little pot and knob.  I sort of emulated the MKIII vernier reduction HF main tuning knob with a larger knob of the same style as the original MKII  knob.

73 de Chris AJ1G Stonington CT
Sent from my iPhone

> On Jan 24, 2024, at 11:09, Ray Fantini <RAFANTINI at salisbury.edu> wrote:
> 
> 
> Anyone have any EF-39 tubes they want to sell? Have been working on a British PCE receiver and one of the EF-39 tubes was missing. Looked to be a fairly standard 6K7 and have a 6K7 stuffed in there now but would like to find the British tube because the EF has a sprayed-on coating that acts as a shield and the old-style glass 6K7 does not. Can use a smaller 6K7 that has the meatal shield but that just don’t look right with all the other tubes being big glass bottles. This tube is the first RF amplifier and without the shield it will pick up noise and would benefit from having a real shield.
> The receiver fits into a meatal WS-19 style case so maybe it’s not an issue when it’s in its case? Think it may be the same case as the WS-19 but would not swear to it.
> The receiver has a nice sound to it on the broadcast bands and SW but if anything suffers from being a bit too sensitive. Checked the AVC action and that’s all working, dose not distort just wants to pick up any and all noise and interference around and unless you are tuned to a strong signal the noise from modern living can be an issue, don’t know if that may be because I am using a 6K7 in the RF amplifier and it’s too ‘Hot” or that’s just the way PYE built it.
>  
> Ray F/KA3EKH
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