--- In ham_amplifiers@..., R L Measures <r@...> wrote:
High value wire-wound resistors have a well deserved
reputation for opening up - even when operated well within the
mfg's max-V rating.
### depends how they are mounted and or supported. The newer 5%
tol units made by Ohmite, IRC, clarostat, dale etc... have never
given me any problems. You can get high wattage, metal
finned units... from dale etc.... dunno about v rating.
### If really paranoid... GLOBAR makes a complete line of low +
high wattage non inductive HIGH VALUE resistor's.
## I have also seen where two separate strings of bleeders were
used. In the 3 k-ultra case.... use 40 k units. You would still
end up with the same 100 k in total.... but if one resistor
anywhere ever opened.... you are UP to 200 k total..... still
better than a wide open. A better scheme is to use the same
10 x 40 k resistor's.... but wire em series/parallel. Then if
any ONE resistor opened up anywhere.... you only go UP to 120 K
total... slick... and would work good. Damn good idea... dunno
why I didn't think of it b4 !
### Just replace all 5 of em... I doubt you will have any more
problems. It would be very interesting to see what value of
resistance... the 4 x remaining old ones are ??? If they
drifted... the highest value one would be the hottest. They
were/are running blazing hot as is. A 100 w rated wire wound..
diss 60 w is HOT.
Later... Jim VE7RF
