The 8877 can not be faulted for failure in HF service due to
gold-sputtering from the grid because that problem is the failure of
the designer to take into account the 8877's extraordinary UHF gain.
Even though the anode-cathode feedback Xc is low at HF, at UHF, the
anode-cathode Xc can be only a few k-ohms -- which is undoubtedly not
good news for a tube with an amplification factor of 200.
- When, on their spec sheets, Eimac says "Maximum Ratings for
Amplifier and Oscillator Service", they aren't fooling.
On Feb 24, 2005, at 7:05 AM, Dennis Sokol wrote:
> The main point of my post was the ruggedness and reliability of the
> 3CX1200A7 tube in the AL-1200. It has one of the lowest failure rates
> of any transmitting tube made by Eimac. The 8877, in contrast, is much
> more delicate and has a history of premature failures.
>
> Just look in the shacks of the major contest stations and see the
> number of AL-1200's used versus the AL-1500.
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>
>
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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