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Trade Chat 30F27 VHF Tetrode

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Nuvistor
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I found this advert in WW Jan 1961 for this valve, I have not seen it used in a TV tuner, we were Ekco agents and they used Mazda valves at that time but I don’t recall this one. 
It seems to have been too late to market as the PC97 Frame grid RF triode came out also in 1961 making the VHF Tuner RF amp much simpler for similar gain and noise figure compared to the cascode or even perhaps this Tetrode.

Anyone else seen it used?

IMG 3750

Frank

 
Posted : 04/12/2024 9:39 pm
malcscott
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Never heard of it, new one to me.

 
Posted : 05/12/2024 5:22 pm
sideband
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Maybe it was one of those that never really got going.....the PC97 perhaps got the upper hand and the 30F27 just fell by the wayside 🤔 

 
Posted : 05/12/2024 8:26 pm
Cathovisor
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I typed the number into Radiomuseum.org and it came back with no results.

 
Posted : 05/12/2024 8:55 pm
Nuvistor
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Another look around the web and I found this from David on the UKVRRR forum from 7 years ago. I don’t remember that thread but lots of info from David and Synchrodyne.

https://www.vintage-radio.net/forum/showthread.php?t=141580

30F27 specification 

https://tubedata.edebris.com/sheets/147/3/30F27.pdf

 

 

Frank

 
Posted : 05/12/2024 10:26 pm
Cathovisor
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I noticed mention of aligned grids to reduce both noise and screen current; the first valve I recall to do that was the Philips/Mullard EF8, which was christened "the Silentode".

 
Posted : 06/12/2024 11:29 am
irob2345
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Silent Toad?

Here is a link to the datasheet.

https://frank.pocnet.net/sheets/147/3/30F27.pdf

Conceptually much like the later 7 pin 6GK5 that we knew in Oz, made by AWV and used in MSP and EIL (Astor) tuners. Never seen in a Philips tuner here, they stuck with the 6ES8 right up to the end.

 
Posted : 07/12/2024 9:27 am
irob2345
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And here is a link to the 6GK5.

https://frank.pocnet.net/sheets/049/6/6GK5.pdf

Doesn't look very exciting! But this valve was widely used and it worked well.

Here it is in an MSP tuner:

6GK5 in MSP tuner
 
Posted : 07/12/2024 10:55 pm
Nuvistor
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@irob2345 The 6GK5 looks a very similar valve apart from heater and some slight specifications to the PC97.

The tuner biscuits in that photo of the tuner look very familiar but can’t recall which UK tuner they were used in. AB Metals Ltd made many tuners for UK TV sets.

Frank

 
Posted : 08/12/2024 10:25 am
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