Henry 2k

[wd0cfc]

I just got a henry 2k with 2 3-400 are they any upgrades or mods for this amp? Any advice is welcomed.

[DMOD]

One of the first upgrades is a tube change to 3-500Z's.

The pin-out and socket is the same.

You may have to get a different set of chimneys, as the chimney specs are different: The 3-400 takes a SK-416 whereas the 3-500 takes an SK-406.

Here is a power supply upgrade for my 2K-4 but can be adapted for your upgrade after the 3-500Z is inserted.

[WQ9E]

Well no need to upgrade the 3-400Z tubes if they are still good.  You will require new chimneys if you change tubes.  Either tube is fine for the design power capability of the 2K.

I did change to 3-500Z tubes in my Drake L-4 so I could liberate the stock 3-400Z tubes for use in a tubeless Hallicrafters HT-45.  That amplifier is so vertically compact that even the 3-400Z plate connection is close to the shield and a 3-500Z would never fit.

[WBear2GCR]

Depends entirely upon which vintage and model "2K" you have.

There are three or four main variants.

Early 2k-3s did NOT have the zener bias for the outputs.
That looks like a transistor on the back panel.
If you do not have a bias set up for it, it's likely a good idea to put it in.
Check the resting current for the output tubes.

If the 3-400s work ok, leave 'em in!

The ballast resistors on the PS often crack, inspect carefully.
Measure the HV, if it is high, that may indicate bad resistors (the big power resistors).

Also the plate meter is monitored off a resistor, if that opens, you blow the plate meter which is 100% unobtainium, and can't be substituted for because it is a flush mount and they don't make them any longer. Put in a meter protection circuit.

Lots of blown Henry 2K meters around.

tell us the model and put up a pic of the front panel...

                    _-_-bear

[wd0cfc]

ok here some pics

[W2VW]

3-500s are not zero bias at the amp's voltage. 3-400s are. Spurious apostrophes optional.

[WBear2GCR]

That is an early 2K.

The big resistors on the left side of the PS pic should be checked for cracks.
If they are not open, and on resistance, and the PS B+ voltage is ok, then leave
them alone, but be aware if the B+ jumps up then one or more may have cracked
and opened.

The zener bias could be implemented with a small rotary switch on the back panel
and a diode or zener string, or could be done by other means, making it easy to swap in 3-500s.

The mod circuit shown earlier cuts off the bias for xmit. The bias shown presumably is to keep the tube at lower current during non transmit? Guessing.

Dave, VW makes an astute point regarding the tubes.

                         _-_-

[wd0cfc]

Are they a good amp? And what all do i need to get to do the mood for the 2k   i was told to use a string of diodes to set the bias and could put a swits at 2 points to adjust bias to what i was doing am or ssb cw  any help i can get is great cause i dont want to burn it or me up lol

[K1JJ]

3-500s are not zero bias at the amp's voltage. 3-400s are. Spurious apostrophes optional.

You mean I've been making tubes possessive all these years and nobody ever told me?      

T

[W3RSW]

Good one.

Didn't understand the quote until I saw your response.

I've always just copied the literature...  What ever looked right in the tube ads.

[DMOD]

The mod circuit shown earlier cuts off the bias for xmit. The bias shown presumably is to keep the tube at lower current during non transmit? Guessing.

In receive mode, the two resistors in series provides a cutoff bias of about 25V.

In Transmit, the 10k is shunted by the relay contact and the Zener provides an 11V bias.

The modification reduces the internal chassis heat load by about 450 Watts by removing many of the original lossy components.

The only disadvantage is the replacement of the TRIAD transformer with a more expensive Peter Dahl type.

Specs:

Resting Plate Voltage - 3,750 volts

PTT, no carrier: Plate Voltage - 3,650 Volts
Plate Current - 140mA

Power gain - Averages 12 dB or better over most bands
No modulation AM exciter carrier input of 25 Watts: Power Output - Legal Limit 

The only thing I don't like about this Henry series is that it doesn't tune for 160m. 

[DMOD]

Are they a good amp? And what all do i need to get to do the mood for the 2k   i was told to use a string of diodes to set the bias and could put a swits at 2 points to adjust bias to what i was doing am or ssb cw  any help i can get is great cause i dont want to burn it or me up lol

They can be good amps with a little TLC.

If this is a 2k (not 2k-3) with 3-400's and the two 3B28 mercury rectifiers, this one is a zero bias linear.

No diode strings needed to bias it.

Note also that you have a number of delay relays that must be functioning.

I assume you have a schematic, experience with and tools for High Voltages?

http://bama.edebris.com/manuals/henry/2K/

[wd0cfc]

yes i have tools and i see today as i have the manual i have the factory manual that came with the amp when it was new that it is zero bias. I know it needs some tlc which it deserves hopefully when i am done it give me many years of service

[WBear2GCR]

protect the meters.

that's the biggest mod to do, imo.

             _-_-

[W2VW]

If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

[DMOD]

 

If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

Not sure what you mean here but the time delay relays are there to protect the 3B28 zenon vapor HV rectifiers.

You need at lest 10 seconds of filament heating before the HV is applied. Henry chose 20 seconds just to be safe.

[W2VW]

If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

Not sure what you mean here but the time delay relays are there to protect the 3B28 zenon vapor HV rectifiers.

You need at lest 10 seconds of filament heating before the HV is applied. Henry chose 20 seconds just to be safe.

Ah. I didn't even consider the hollow state rectifiers. Thanks.

[wd0cfc]

i had a new set of solid state rectifiers gave to me brand new never used

[wd0cfc]

Is this right a triad 16078 in my 2k i just wonder cause i see holes in bottom where it bolts down

[WBear2GCR]

Hard to know... my Henry 2k3 has an open frame type transformer.

Give us a wide shot of the power supply?? you have the pedestal style?

Extra holes do not in themselves have great meaning.
And anyhow if the transformer works, meets specs, it is the "right" one.

                _-_-

[wd0cfc]

ok here is a pic

[Jim/WA2MER]

I have the same amplifier.  Same holes as yours has.  Your xfmr looks to be the correct one.

[W3RSW]

Glad you got that ironed out,
And couldn't resist,
If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

Try Carol and Alice  

[Pete, WA2CWA]

Glad you got that ironed out,
And couldn't resist,
If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

Try Carol and Alice  

You show an active link to nowhere: If the time delay quits so what. Extra crap. Can't ask Bob or Ted.

And, if you desire, you can really ask Ted Henry: Henry Radio (800) 877-7979, ext. 310

[W3RSW]

Pete,

I mistakenly used the "world" symbol to encase the quote and had a devil of a time trying to delete it with this "-(:& IPad.  As you know, one has to guess ahead of time what it will do to one's spelling, syntax and intent.

Further, since I duplicated the sentence exactly and properly for a quotation, I thought that most would realize it was a corrected duplicate.

Yours in antimoderation, 
R. Esq.