> have kicking around. Of course when I buy an Sb-220, the
> band switch is not
> my concern so no sweat. I have had several Drake L4B
> amps and never did I
> see a bad band switch on one of them. Even the Dentron
> and Amp Supply amps
> have better band switches.
The switch in the SB220 is exactly the same wafer style and
manufacturer as in many Dentrons and Amp Supply amps of
similar operating HV.
That switch is good for normal mistuning at about 3000 volts
maximum supply voltage.
Amp supply and Dentron did use some larger JV-9000 series
switches, but not as a general rule in 3000 volt and lower
amps.
> As to why they burn up? well that discussion could
> land you in jail :-) The 2 Sb-220 amps that I actually
> ever used on the air
> I bought as kits and built myself so I knew the condition
> of the band
> switch. I used an Sb-220 for many years and got good
> service form it. Careful
> tuning kept it in good condition.
Bingo. Careful tuning implies the HV is not extreme.
See:
http://www.w8ji.com/demonstation.htm
73 Tom
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|