>VO1MP Gus Samuelson
>St. Phillips Newfoundland
>
>
>> >Well after what turned out to be a successful repair
>> >I notice that my TL-922 has now developed an intermittent
>> >IP reading of about 100 mils while idling in the 2000V position
>> >and about 1.5 mils in the 3000 V position .
>> >Out put is not affected and for the first time in along while
>> >the amp with a pair of brand new Eimacs is delivering full power.
>> >If I get an opportunity over the Christmas break I will take the
>> >covers off again.
>> >Any suggestions where I should look first problems ?
>> >
>> Is the 922 completely stock?
>> - thanks
>>
>>
>> Rich...
>>
>> R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
>
>
>Yep Rich .... only mod here is the 10 meter
>that I did in November 1988 according to my Manual.
>
ok
>In any event the manual says I SHOULD SEE
>150ma IP when in LP operate mode or sty mode
is "sty mode" standby mode?
>and 200ma IP in HP mode.
>I think now that the thing is operating properly for the first time
>and I'm not accustomed to seeing it that way ??
If you have any Ip on standby, 'the thing' is on the verge of a serious
meltdown.
> Still would like to know why the IP meter occasionally
>does not have any reading in idle or standby mode as
>suggested by the manual ?
If the Ip meter indicates current in standby mode, odds are that a
grid/fil. short is taking place. In a stock TL922, a grid/fil. short
applies 0V bias to the tube, which causes Ip to flow during standby *And
Shorts Out* the +110v supply during standby. Since the +110v supply is
powered by a winding on the fil. transformer, unless the amplifier is
switched off, the (unfused) fil. transformer will be destroyed. This
scenario can be avoided by snipping the wire between the coil (+110v) of
the bias relay (near fan) and the nc bias contact on the relay. (see
Circuit Improvements for the TL-922 article on my Web site)
>Oh well if it ain't broke mebbe I shouldn't fix it.
>
? A stitch in time saves 9, Gus
>
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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