>Rich Measures wrote:
>
>> ? I did not state that the arcs occurred during 10m operation. I stated
>> that the arcs occurred at the open 10m contacts. The photo of the
>> toasted bandswitch in the QST article "Parasitics Revisited" Sep.,
>> Oct./1990) shows a bandswitch that was damaged during 40m and 80m
>> operation, when the 10m, 15m and 20m contacts were open. In the
>> photograph, the 10m contacts are those with the most damage. The 20m
>> contacts are the least damaged.
>> - later
>-------------------
>
>I first worked on an SB220 as a Heathkit tech
? bingo
>........
>Since then I've owned, serviced, modified or for some reason had
>my hands inside 20 or 30 SB220s (not the 200 Rich has tested).
? I did not state how many I worked on. My guess is fewer than ten.
>In the 220s Ive worked on with bandswitch damage that damage
>can be directly attributed to the operator rotating the band switch
>instead of the load control while tuning up. ......
? When an amplifier's tank is out of resonance are the tank voltages
maximal or minimal? Does it make sense that rotating the bandswitch
would toast V2's vhf suppressor resistor and simultaneously implode its
grid to gnd pi-wound RFC? // Kenwood factory service techs used to
tell customers with burned up TL-922 bandswitches that their bandswitches
burned up because the (obviously stupid) operator turned the bandswitch
while tuning up. .
Ford originally claimed that they had no idea why Pintos were turning
into door-jamming instant family crematoriums upon rear impact.
Unfortunately an internal memo turned up which revealed that the problem
showed up in factory testing. However, after the gas-tank protection fix
was determined to cost c. $20 per Pinto, Ford management made a "right"
corporate decision. And as a result, over 200 eventually met with the
same infernal fate as Joan of Arc.
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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