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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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29th Nov 2022, 10:57 am | #21 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,578
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Re: Stable ECL80 Amp?
Well if you can use a PCF80 as a sound output valve why not use an ECL80 as a frequency changer.....?
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29th Nov 2022, 10:27 pm | #22 |
Nonode
Join Date: Jan 2009
Location: Papamoa Beach, Bay of Plenty, New Zealand
Posts: 2,944
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Re: Stable ECL80 Amp?
Pye’s use of the ECL80 as a Band I TV frequency changer was described in IEE paper #1294 of 1952 May, “The Design of a Superheterodyne Receiver for Television” by D. H. Fisher and A. J. Watts.
The writers noted that that although the conversion conductance of the only available triode pentode (i.e. the ECL80) was less than half that of a typical TV pentode, nonetheless, in this case (with a high IF), it was better than either a self-oscillating pentode or a double triode frequency converter. They then went on to say: “The authors note with regret that there appears to be no efficient triode-pentode available on the British market suitable for frequency-conversion service at the frequencies under consideration.” The first American TV frequency changer triode pentodes, 6U8 and 6X8, had been released around 1951 August plus/minus, so the authors were probably aware of these. In the UK, the Mazda 10C2 would have been imminent, if not already released, at the time the paper was read, but perhaps unknown when it was written late in 1951. Be that as it may, if the ECL80 could be made to work as a frequency changer at Band I, then perhaps it would also work at HF, which would make it a frequency changer candidate for the receiver concept that is the subject of the thread: https://www.vintage-radio.net/forum/...d.php?t=195648. Cheers, |