Regardless of what the correct plate voltage should be, he says his was at 3400
volts and now that has fallen a considerable amount with output power going
down with it. This would seem to indicate one of two things, either the primary
main voltage has dropped or something has happened in the power supply to cause
the drop in voltage or loss in output. I addressed the problem, not what it is
supposed to be. I have seen a hundred of these amps and very few have the
factory parts in them as they started life so his first statement of 3400 volts
could be absolutely correct. As far as heavy duty goes, I don't think I could
put any Hunter amp in that category.
----- Original Message -----
From: Carl
To: Tim Kass ; Charles Hedrick ; amps@contesting.com
Sent: Sunday, July 17, 2011 11:44 AM
Subject: Re: [Amps] Hunter 2000c Low Output.
That is the correct standby voltage and it should drop to 2200-2300 under
full load.
I dont understand why the Eimac 3-400Z should be a problem. It is a little
harder to drive but otherwise a zero bias compatible tube. Ive swapped them
as well as mixed in other 3-400Z amps.
Hunter claims either are permitted altho the Amperex is recommended likely
since its a bit easier to drive.
The same with a 3-500 as it should run fine at zero bias at that voltage
altho about 5.1V bias will improve the IMD about 6dB.
Carl
KM1H
----- Original Message -----
From: "Tim Kass" <k8wbl@yahoo.com>
To: "Charles Hedrick" <cchedrick@gmail.com>; <amps@contesting.com>; "Mitch
Cox" <ww4cox@embarqmail.com>
Sent: Sunday, July 17, 2011 11:03 AM
Subject: Re: [Amps] Hunter 2000c Low Output.
I also have the wonderful Hunter 2000C amp... My standing voltage is 2700
VDC...same caps ... this amp has a diode block arrangement, very heavy duty
parts. Make sure you are running the AUX LOAD in the 0 position on the lower
bands and try it again it a dummy load on 40 meters to start. ALSO -- this
amp was designed for Amperex 8163 (3-400z) and mine ran well with the
original 8163's in it...however, I have tried several pairs of Eimac 3-400z
and it doesnt like (2) running together....very low output...300 watts..
take one of the tubes out and run it briefly as a single tube and see what
output you get... I now run a single 3-500Z Eimac and does well..got some
more coming to try to run a pair of them.. but if you amp runs fine on the
single tube...you can then eliminate some of the other issues... high SWR
input from solid state tubes doesnt seem to bother it to much but I have an
IC-746PRO and use the internal tuner to balance things..but unless
the SWR is over 3:1 between the radio, the amp doesnt seem to mind... I
also use the Heathkit AMPKEYER for good measure. Great amp, I have had 2 of
these..will never sell this one..
73, Tim K8WBL
--- On Sun, 7/17/11, Mitch Cox <ww4cox@embarqmail.com> wrote:
From: Mitch Cox <ww4cox@embarqmail.com>
Subject: Re: [Amps] Hunter 2000c Low Output.
To: "Charles Hedrick" <cchedrick@gmail.com>, amps@contesting.com
Date: Sunday, July 17, 2011, 12:30 AM
The first thing I would be looking for after first checking the incoming AC
voltage would be an open rectifier or capacitor in the power supply section.
But first you need to make sure that the incoming line voltage is where it
should be. From the report of a bad match between the radio and amp you
almost would want to look in the bandswitch section of the tuned input if
one exists but that would have no effect on the plate voltage.
----- Original Message -----
From: Charles Hedrick
To: amps@contesting.com
Sent: Saturday, July 16, 2011 10:11 PM
Subject: [Amps] Hunter 2000c Low Output.
HI All,
This has me puzzled. HV is 2800 down from 3400 which is normal in this
small town this time of year. I noticed yesterday that the power level was
fluctuating weirdly up and down. when tuning the amp into the dummy load.
So last night I installed new 3-500ZG's and cooked them for 24 hours. I
just tried the amp again and the power out is way down, the rig is seeing a
high SWR. Bad Tubes....I just pulled a pair from the AL-82 and got the same
results. I installed the new pair in the AL-82 and got 1300 key down with
65 watts drive. The HV on the hunter doesn't fluctuate, and I'm .38 amp and
300 output with HV dropping to 2400 at key down. The AL-82 is seeing the
same HV drop by the way, but handles it better, 85 watts drive is 1500 CW
with the new tubes. Parasitic Suppressors bad? Stumped here.
Thanks,
Cam
WA4JKW
NCS MMSN
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