Pye 45 Mc/s Radar IF module

[SteveCG]

These modules were on the UK war surplus market after the Second World War. They used EF50 Valves (or to be more accurate, their Service versions). However they are said to be based upon the vision amplifier module for a Pre-War, 405 line, TV (a TRF design centred on 45 Mc/s).

Does anybody know whether a particular TV design was copied? - And if so was it adapted to use EF50s ?

Finally: Is there a circuit diagram for the module 'out there' in web-space?

[HamishBoxer]

They were used post war as an IF strip in home brew television.The EF50 without checking certainly up and above 45mcs. Practical Television mag ran an article in the 1950's on building a TV with them.

Or, have I missed the question?

[SteveCG]

Well, HamishBoxer I was thinking of the Pre-War TV (Televisor?) that the IF unit may have been designed from, that is, the progenitor of the IF unit. Sorry if I was not clear.

[trh01uk]

Hmm, interesting question. These IF strips were designed by Pye, and were adopted by the radar boys to put into many different radar equipments designed during WWII. The EF50 itself was extremely new, and one of the first European valves to operate above 30MHz reliably. In the early days of the war, there was a serious shortage of EF50s, and some equipments had to have them designed out again (swopped to VR65s for instance).

But the question you are asking is whether Pye had a specific TV set in production which used this IF strip? And can we get a schematic of the actual strip that Pye designed?

I've no idea what the answer is to either question myself - but I am quite interested to see what the answer will be (assuming someone on here actually knows of course!). I can certainly turn up the schematics of things like the H2S radar that used this type of IF strip - though the frequency did vary from one equipment to the next.

Richard

[ms660]

Pye 915? 2nd para:

https://www.rafmuseum.org.uk/blog/sm...ect-big-story/


Lawrence.

[SteveCG]

This may be relevant: Sir Martin Ryle, who was at TRE during the war, and then founded Cambridge Radio-Astronomy after the war, had dealings with the H2S radar system that used the Pye IF strip, as mentioned above by Richard. And Cambridge Radio-Astronomy definitely used these Pye IF strips in their early days. Perhaps he was impressed with them? Or perhaps he knew how to get hold of some after the war !

Here is a link to a .pdf from the Royal Society on Ryle's life:

http://rsbm.royalsocietypublishing.org/content/32/496

A bit OT, in the late '70's (when but a mere teenager) I had a tour of the Cambridge telescopes courtesy of the local radio club. Saw lots of things, walked around under Jocelyn Bells telescope and had a talk from Martin Ryle sat in the control room, fascinating. The mile long railway line for some of the dishes is dead flat i.e. it goes up at the ends some inches to correct for the curvature of the earth.

[SteveCG]

Lawrence,

This link to a Pye web-site rather confirms the 915 as being the TV set.

http://www.pyemuseum.org/divisions/c...istory_pt1.php

Next question: Who has a circuit diagram of this venerable set?


This Pye web-site has a photo of the IF unit and info on the IF unit's use

http://www.pyetelecomhistory.org/pro.../military.html

[ms660]

I'm sure I read once on the VRAT forum ? of someone who had the Pye 915 schematic...possibly.

EDIT: Found and added link ref. above:

http://www.forum.radios-tv.co.uk/vie...php?f=5&t=7652

Lawrence.