[Amps] SB-230 Power Question

[Roger (K8RI)]

On 3/19/2013 3:55 AM, K4MT wrote:

Its been a very long time since I owned an SB230 (bout 30-35 years, but 
IIRC this is pretty much typical.

73

Roger (K8RI)


> I recently acquired a SB-230 thinking the tube was probably bad with an idea of doing a GI7B project. To my surprise the amp puts out 650 watts plus on my peak reading wattmeter on SSB 80/40 Meters with 100 W drive..
>
> On the bands from 20 and up the power output drops.  20 Meters is about 550, 15 meters about 350-400 and I  have not tried 10m.
>
> I recapped PS, rebuilt tube grid circuit and repaired some bad soldering and out of tolerance parts, replaced grid bypass capacitors, removed entire tank circuit and band switch. Cleaned bandswitch and cleaned/resoldered all connections.
>
> Still power on higher bands drop as above.
>
> Any experts on this amp out there who might have an idea what might be going on. Is this a sign of a weak tube?  Since I get so much power output on 80/40M I would think the tube must still have some life in it.
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>