[Amps] Item # 170692212503

[Roger (sub1)]

On 9/6/2011 3:02 PM, Roger (sub1) wrote:
> I was reading the description of this Alpha 6-meter amp that claims
>
> "Robust 4CX1600B (Svetlana GU-91B) which is very affordable and readily
> available."
>
> ** Has the 4CX1600B gone back into production? It's listed as a GU-91B
> from the company that took over Svetlana but I've not found any source
> for them.

The last 6-meter Alpha I saw advertised (on their site) uses a 
4CX1500B.  I'd think a good replacement might be the Chinese FU728F.  As 
the FU728F has a slightly larger centering pin (bout 0.003") it should 
fit the socket nicely.  The only change needed would be a different 
filament voltage and adjust the bias. It should add a good 30% of 
available overhead.  Only downside I can see is what appears to be a 
rather high infant mortality rate for the FU728F

73

Roger (K8RI)
>
>
> 73
>
> Roger (K8RI)
>
>
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