Aloha Val,
Thanks for the reply. The repairs I did were replace the power cord hooked-up
for 220V, all the High-Voltage wire as the old was dry and cracked. Some of the
bleeder resistors had some bad solider connections so I repaired them they are
all good R9 seems to be good I get continuity through it. I did test the
voltage on the transformer before I reinstalled the HV filter bank and it
checked fine @ 3100V with a Simpson 260 & a 5000V probe. It did not blow any
fuses or trip the main breaker just smoked a filter cap and shorted one. I do
belive it is the filter caps are just too old and have been sitting too long.
Thanks for the reply
Roland AH6RR
----- Original Message -----
From: Val Erwin
To: Roland AH6RR
Sent: Saturday, December 12, 2009 2:07 PM
Subject: Re: [Amps] Excessive Plate Voltage Henry 2KD-5
Hi Roland:
Suggest that you check the ac primary wiring to ensure that you have
the amp jumpered for the proper AC voltage......I trust that you have it set up
for 220 vac. (If-if you applied 220 vac to the primary with it wired for 110
vac, the DC voltage could shoot up and you would likely blow a fuse as well!!)
I am suspicious of your wording: "...........after doing some repairs
,,,,,,,,etc," Suggest you go back and check your work especially if it was any
rewiring!
If you have a shorted capacitor, you are on the right track.........Due
to the age of the amp, you really need to replace the caps (C1-C8) as well as
the combo bleeder/equalization resistors (R1-R8) Also, while you are in the
area, check the integrity of R9 to make sure it is still good.
After you have replaced the caps/resistors, I would recommend that you
pull the plate caps off of both 3-500Z's just in case the HV is still too high.
(At this point, I am going to assume that your new tubes are still good.) Then,
you can check your new HV reading after the component replacements with no fear
of damaging the tubes.
Is there any way of knowing this will fix the problem before you spend
the $$?........No not really because there could be other things that are bad
such as meter shunts, etc. There is a test that you could run before replacing
all the caps .....But, for safety reasons, I will not convey how to do that
test because it can be dangerous if not experienced with HV and and amp
repair/troubleshooting.
GL
Val L. Erwin / W5PUT
Flower Mound, TX
--- On Sat, 12/12/09, Roland AH6RR <Toesonnose@hawaii..rr.com> wrote:
From: Roland AH6RR <Toesonnose@hawaii.rr.com>
Subject: [Amps] Excessive Plate Voltage Henry 2KD-5
To: amps@contesting.com
Date: Saturday, December 12, 2009, 10:14 PM
Aloha All,
I have a Henry 2KD-5 that has been sitting for a few years and after
doing some repairs and tube replacement I turned it on and the plate voltage
went to 4000V before I could turn it off. One of the filter caps smoked and now
1 has a short they all seemed hot, they are the orignal filter caps. I plan on
replacing the all but I want to know if this will cure the problem. I checked
the HV supply wiring and it is fine. Should I look at anything else?.
Roland AH6RR
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