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Henry 2K2

D

datsun66

Active Member
Apr 10, 2005
251
15
48
Lewistown, Montana
Ok fired up the henry 2k2 on 220vac. What I did see was the 3-500zs come on and light.
I used a ft101E as an exciter and I did tune it up on am and with a low carrier into the amp and keyed it up into a dummy load. What i did see was the tubes did get warmed up pretty good and in fact as I turned up the exciter the tubes got down right hot and glowing more that I wanted to see. I didn't let this happen for more that a few seconds but the output was low but the tubes did glow hotter the more I turned up the carrier. If you go to my pics on my station you can see this amp has been in fact changed a lot.
Any ideas on why this would happen to the tubes? Low output the higher the carrier the more the tubes would glow hotter.
 

datsun66 said:
Ok fired up the henry 2k2 on 220vac. What I did see was the 3-500zs come on and light.
I used a ft101E as an exciter and I did tune it up on am and with a low carrier into the amp and keyed it up into a dummy load. What i did see was the tubes did get warmed up pretty good and in fact as I turned up the exciter the tubes got down right hot and glowing more that I wanted to see. I didn't let this happen for more that a few seconds but the output was low but the tubes did glow hotter the more I turned up the carrier. If you go to my pics on my station you can see this amp has been in fact changed a lot.
Any ideas on why this would happen to the tubes? Low output the higher the carrier the more the tubes would glow hotter.
Click to expand...

What did the input VSWR look like? As the tubes started turning more orange red did the VSWR rise on the input?

You may try gettering the tubes to see if that will bring them back to where they can be used again.
 
The Henry amp is so far away from the original It would be hard to follow. There were no schematics to this rig. The plate transformer takes up half of the cabinet. Anyhow. I looked into the rf deck and I found that there is another what looks like a plate choke installed in there. I was getting 2100 volts on the plate. If you want to I did take a couple of pics of the amp and you can see what was done. I stored the pics here. http://www.worldwidedx.com/members/datsun66-albums-datsun66-ham-shack.html
I can take some pics of the rf deck also but if this thing is to wild I could start from scratch.
All of the parts are already there.
Ideas?
PS, when I did the test it was hooked up to a cantenna.
 
OK on being major modified.

Couple of questions.

What freq or band did you try checking the Henry on?

10 meters will show a bad tube quickly as far as being gassy.

Try this test to See what it looks like.
transceiver-swr bridge or meter-Henry-power meter-dummy load.

With 10 watts of carrier tune the amp, look at the input vswr. Then apply more drive to get around .4 IP current making sure you have dipped the plate for resonance. See what the input vswr does then. If IP rises as well as input vswr then it is bad tubes usually. If the input vswr stays good then there may be some issues with the tank circuit.

I had an amp on the bench couple weeks ago, 15 through 80 meters was great, full output. 10 meters was wacky as can be. The input VSWR and IP both begin to rise after 20 watts of drive applied. Replaced the tubes and all is well with it now, amp is back to the owner and he is having a blast with it.
 
Love working split shifts.
Answer to question#1- I was on 20 meters
The tubes look as if they are new. Clear glass and the lettering is near perfect.
I do need to find out what he was doing installing 2 plate chokes in the amp.
 
wavrider said:
OK on being major modified.


Try this test to See what it looks like.
transceiver-swr bridge or meter-Henry-power meter-dummy load.

With 10 watts of carrier tune the amp, look at the input vswr. Then apply more drive to get around .4 IP current making sure you have dipped the plate for resonance. See what the input vswr does then. If IP rises as well as input vswr then it is bad tubes usually. If the input vswr stays good then there may be some issues with the tank circuit.

QUOTE]

The test mentioned still needs to be performed before any sort of conclusion can be drawn.

the 3-500Z are designed to glow orange red and they should glow in normal use. ( you should see that 4-1000A glow when I am driving it hard).

the tubes will glow brighter when mis tuned, once they are tuned up, you can actually see the "glow" increase with your voice peaks on SSB.

so when your schedule permits lets try that test mentioned above and post results please.
Click to expand...
 
Captain Kilowatt said:
Yes, the Henry 2K2 did use the 3-400 tube but the 3-500 is a drop in replacement. The only difference is the extra 100 watts of dissipation because of the heavier anode.
Click to expand...

Plus about a half inch in height difference, also a cathode bias circuit is highly recommended for using the 3-500Z in place of the 3-400Z, keeps that idle current low.
 
wavrider said:
Plus about a half inch in height difference, also a cathode bias circuit is highly recommended for using the 3-500Z in place of the 3-400Z, keeps that idle current low.
Click to expand...

The 3-500Z is good without bias,it's about as close to zero bias as you can get, when run at less than maximum plate voltage and the 2K2 does not run them anywhere near max plate voltage so either should be fine in that amp. As for the height, yes that can be a problem in a few amps, like the Swan Mark 1, but most amps have the extra room without dropping the tube sockets below the chassis.
 
2100v? isnt that about half of what those tubes like? My old 2kd provided about 3600v
 
Captain Kilowatt said:
The 3-500Z is good without bias,it's about as close to zero bias as you can get, when run at less than maximum plate voltage and the 2K2 does not run them anywhere near max plate voltage so either should be fine in that amp. As for the height, yes that can be a problem in a few amps, like the Swan Mark 1, but most amps have the extra room without dropping the tube sockets below the chassis.
Click to expand...

According to the owner's manual, around 3200 v dc sitting on top of those tubes.

At the price of tubes today I would much rather have an idle current of 60ma compared to 200ma without any cathode bias.
 

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