>
>Peter Sundberg wrote:
>>I am perfectly comfortable with my QBL 5-3500 G2DAF amp without any
>>parasitic suppressor. It runs all bands, stable as a rock. No special
>>arrangements except the screen is bypassed with a PTFE "sandwich"
>>capacitor, same technique I use in the VHF/UHF amplifiers. Also the wiring
>>between input and output is done to preserve as much isolation as possible.
>>The tube has full specs (4kW out) up to 110 MHz so it is not like the 813's..
>>Supressors not needed in all amps it seems..
>
>This ties in exactly with what Tom was saying. If you build HF
>amplifiers with the kind of "VHF awareness" that Peter has, you don't
>have many problems with unexpected VHF resonances.
>
>On the other hand, if you build an HF amp using only "LF awareness",
>with long leads and unsuitable components that behave strangely at VHF,
>you can get some very nasty surprises!
>
I have spoken with a number of AL-1500 owners who got some nasty
surprises.
end
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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