Hello Steve,
Tuesday, September 20, 2005, 9:19:04 AM, you wrote:
ST> You could see the same effect if the tank coil inductance is too low -
ST> eg if part of it was shorted out when it should be in circuit.
ST> Max load cap. gives you a high anode load resistance. The circuit might
ST> like this if the ht was higher than intended, but I can't see runnning
ST> 240V into a 220V input, for example, making enough difference. Tired
ST> valves that don't have the emission to cope with a lower load resistance
ST> might also do it.
ST> What gain and output power are you getting, and how do they compare with
ST> the spec. for the amp? Does the anode current dip - is the dip at max rf
ST> output?
ST> Steve
I was wondering about the tank coil although I've not noticed a
problem with it visually, perhaps adding a turn or two??
The HT runs at 2100 off load and 1950 on load. As I've said in other
replies I have a spare set of valves and switching them around hasn't
helped.
Gain and output seems to be OK, although I've seen that some say they
get more output, on 80 & 40m 80w in gets around 625 - 650w out. As far
as the anode current, dip it is deepest at max rf out.
--
Best regards,
John mailto:kvp@bigfoot.com
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