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I have recently had a little time to investigate my Henry 2K Classic X a little more. The transformers are marked South Gate and the part number on the high voltage transformer is ECA 1171. Quoting the spec:

OUTPUT POWER
2K-Classic X (Export Model) - 1800 watts PEP nominal (3000 watts PEP nominal input).

DUTY CYCLE
2K-Classic and 2K-Classic X- Continuous at rated output.

Soooo...

With about 3300 volts on load (3700 off load) as per the front panel meter. I guess the transformer is good for about 900mA continuous?

Does anybody have a more informed idea about the transformer rating?

As I become more acquainted with this amp it does seem as if the 3-500 tubes are less than the rest of the amp is capable of. I wonder what might be a good candidate for transplant?

Martin, HS0ZED

--- In ham_amplifiers@..., Martin Sole <msole@...> wrote:

I have recently had a little time to investigate my Henry 2K

Classic X a

little more. The transformers are marked South Gate and the part

number

on the high voltage transformer is ECA 1171. Quoting the spec:

OUTPUT POWER
2K-Classic X (Export Model) - 1800 watts PEP nominal (3000 watts

PEP

nominal input).

DUTY CYCLE
2K-Classic and 2K-Classic X- Continuous at rated output.

Soooo...

With about 3300 volts on load (3700 off load) as per the front

panel

meter. I guess the transformer is good for about 900mA continuous?

Does anybody have a more informed idea about the transformer rating?

3300 Vdc at 900 mA would be the DC current required from the
rectifiers and filter C. The AC rms current the secondary would need
to supply would be something like Iac = Sec. Idc X 1.613 where 0.9A x
1.613 = 1.45 amperes AC if it's designed by the recommended standards
for using a FWB with cap input. If it uses a choke input for the
filter circuit though, the rms current needed will be lower. For a
FWB with a choke input, it would be Iac = Sec. Idc X 1.064. Below is
some handy formulas for the two rectifier types.

FWB, C input;

Vdc peak = 1.414 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 0.707

Idc = 0.62 X Sec. Iac

Iac = Sec. Idc X 1.613

====================================

FWB, L input;

Vdc peak = 0.90 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 1.111

Idc = 0.94 X Sec. Iac

Iac = Sec. Idc X 1.064

One would need to know the core dimensions of the transformer in
square inches to roughly determine what its power rating capability
is. That's the tongue width times the stack thickness. It's the same
for EI or C type cores.

As I become more acquainted with this amp it does seem as if the 3-

500

tubes are less than the rest of the amp is capable of. I wonder

what

might be a good candidate for transplant?

Martin, HS0ZED

Best,

Will

Thanks Will,

see below

craxd wrote:

--- In ham_amplifiers@..., Martin Sole <msole@...> wrote:

I have recently had a little time to investigate my Henry 2K

Classic X a

little more. The transformers are marked South Gate and the part

number

on the high voltage transformer is ECA 1171. Quoting the spec:

OUTPUT POWER
2K-Classic X (Export Model) - 1800 watts PEP nominal (3000 watts

PEP

nominal input).

DUTY CYCLE
2K-Classic and 2K-Classic X- Continuous at rated output.

Soooo...

With about 3300 volts on load (3700 off load) as per the front

panel

meter. I guess the transformer is good for about 900mA continuous?

Does anybody have a more informed idea about the transformer rating?

3300 Vdc at 900 mA would be the DC current required from the rectifiers and filter C. The AC rms current the secondary would need to supply would be something like Iac = Sec. Idc X 1.613 where 0.9A x 1.613 = 1.45 amperes AC if it's designed by the recommended standards for using a FWB with cap input. If it uses a choke input for the filter circuit though, the rms current needed will be lower. For a FWB with a choke input, it would be Iac = Sec. Idc X 1.064. Below is some handy formulas for the two rectifier types.

*** The psu is a FWB with a resonant choke input filter.

FWB, C input;

Vdc peak = 1.414 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 0.707

Idc = 0.62 X Sec. Iac

Iac = Sec. Idc X 1.613

====================================

FWB, L input;

Vdc peak = 0.90 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 1.111

Idc = 0.94 X Sec. Iac

Iac = Sec. Idc X 1.064

One would need to know the core dimensions of the transformer in square inches to roughly determine what its power rating capability is. That's the tongue width times the stack thickness. It's the same for EI or C type cores.

*** By tongue do you mean the centre part of the E lamination? That measures about 2"x4". Stack thickness is 5"

As I become more acquainted with this amp it does seem as if the 3-

500

tubes are less than the rest of the amp is capable of. I wonder

what

might be a good candidate for transplant?

Martin, HS0ZED

Best,

Will



Yahoo! Groups Links

Martin,

The iron that's inside the coil is what we need the area in square
inches for. The tongue is the center leg of the lamination. This
tongue width gives us the one dimension we need. The core stack depth
is the other. In your case, I'm assuming the tongue width is 2" and
the stack is 5" thick? If so, that's 10 square inches. To convert
this into the power rating for 60 Hz at 12 kilogauss (about right for
EI lams like M-19 steel), we use the formulas;

TPV = 4.85 / A

A = 0.1725 x sqrt of P

P = ( a / 0.1725 )^2

So;

( 10 In^2 / 0.1725 )^2 = 3,360 watts.

This transformer could be ran at up to 14 kilogauss though, according
to the steel used such as M-6, which is a possibilty that would up
the power rating a little more. The total power though (being it is a
L input filter) should be;

Iac = 0.9 amperes X 1.064 = 0.957 amperes.

0.957 amperes x 3300 Vdc = 3158 watts.

So, the transformer is sized correctly for this type of filter
circuit. If you change it to a C input filter though, the rms current
for the secondary will raise by the amount shown in the formulas.

Best,

Will


--- In ham_amplifiers@..., Martin Sole <msole@...> wrote:

Thanks Will,

see below

craxd wrote:

--- In ham_amplifiers@..., Martin Sole <msole@> wrote:

I have recently had a little time to investigate my Henry 2K

Classic X a

little more. The transformers are marked South Gate and the part

number

on the high voltage transformer is ECA 1171. Quoting the spec:

OUTPUT POWER
2K-Classic X (Export Model) - 1800 watts PEP nominal (3000 watts

PEP

nominal input).

DUTY CYCLE
2K-Classic and 2K-Classic X- Continuous at rated output.

Soooo...

With about 3300 volts on load (3700 off load) as per the front

panel

meter. I guess the transformer is good for about 900mA

continuous?

Does anybody have a more informed idea about the transformer

rating?

3300 Vdc at 900 mA would be the DC current required from the
rectifiers and filter C. The AC rms current the secondary would

need

to supply would be something like Iac = Sec. Idc X 1.613 where

0.9A x

1.613 = 1.45 amperes AC if it's designed by the recommended

standards

for using a FWB with cap input. If it uses a choke input for the
filter circuit though, the rms current needed will be lower. For

a

FWB with a choke input, it would be Iac = Sec. Idc X 1.064. Below

is

some handy formulas for the two rectifier types.

*** The psu is a FWB with a resonant choke input filter.

FWB, C input;

Vdc peak = 1.414 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 0.707

Idc = 0.62 X Sec. Iac

Iac = Sec. Idc X 1.613

====================================

FWB, L input;

Vdc peak = 0.90 X Sec. Vac

Vavg = 0.90 X Sec. Vac

Vac = Sec. Vdc peak X 1.111

Idc = 0.94 X Sec. Iac

Iac = Sec. Idc X 1.064

One would need to know the core dimensions of the transformer in
square inches to roughly determine what its power rating

capability

is. That's the tongue width times the stack thickness. It's the

same

for EI or C type cores.

*** By tongue do you mean the centre part of the E lamination? That
measures about 2"x4". Stack thickness is 5"

As I become more acquainted with this amp it does seem as if the

3-

500

tubes are less than the rest of the amp is capable of. I wonder

what

might be a good candidate for transplant?

Martin, HS0ZED

Best,

Will




Yahoo! Groups Links

--- In ham_amplifiers@..., Martin Sole <msole@...> wrote:

I have recently had a little time to investigate my Henry 2K

Classic X a

little more. The transformers are marked South Gate and the part

number

on the high voltage transformer is ECA 1171.

#### Beware... Henry Radio has gone through more plate xfmr
manufacturers' over the yrs than u can shake a stick at. I was told
they dumped ECA.... and dunno who they replaced with.

### If't it doing 1800w out from 2 x 3-500Z's.... that's plenty.




Quoting the spec:

OUTPUT POWER
2K-Classic X (Export Model) - 1800 watts PEP nominal (3000 watts

PEP

nominal input).

DUTY CYCLE
2K-Classic and 2K-Classic X- Continuous at rated output.

### That doesn't mean 1800W dead cxr all day long......... means
1800 w pep all day long..big diff. Even if it was 1800 w CCS
cxr..... on ssb.. the supply would be good for 50% more... so maybe
2700 w pep out.... if u changed the tubes.... to something like 3CX-
1200's or YU-120's.

Soooo...

With about 3300 volts on load (3700 off load) as per the front

panel

meter. I guess the transformer is good for about 900mA continuous?

Does anybody have a more informed idea about the transformer

rating?

As I become more acquainted with this amp it does seem as if the 3-

500

tubes are less than the rest of the amp is capable of. I wonder

what

might be a good candidate for transplant?

### 3CX-1200's will drop right into same socket. The YU-120 is
the Howell hot rod version... with 1500 w ccs anode diss.... drops
into same 3-500z socket....... then u have to change the fil xfmr
etc.

### You can't just suck twice as much plate current either......
ur plate load Z will drop in half..... which means u need twice as
much tune and load C... and 1/2 as much coil per band. Do
really really want to butcher it.. for a lousy 2 db ?? At that
point, ur ECA brand plate xfmr + mating choke is on borrowed time.
When u blow it up...... then replace with an identical spare new
one.... the spare will blow up as well.

### I'd leave it.... and use it as an IPA.

Later... Jim VE7RF

Martin, HS0ZED

I have converted Henry 3K / 3K-A amplifiers to a single 8877. IT makes for
a nice conversion and they will give you 2KW out reliably with less than
100W drive without blowing up tank components. Just use a blocking plate
available everywhere for the second hole.

The 2K series of amps' power transformer is too low a voltage to get this
kind of power no matter what. The change just needs to be a PETE DAHL soup
up direct bolt in replacement. I had a 2K-4 for a time with the GO FAST
Dahl in it and it ran right alongside any 3K-A.

Generally a dual 3-500Z amp of Henry construction DOES NOT have the tank and
capacitor support to run dual BIG TUBES. Once you pass 2000 OUT stuff BLOWS
UP FAST.

I completely agree with JIM, I'd not mess unless this unit was BROKEN. You
know blown tubes, burned out transformer, exploded tank circuit, etc. If
she's sweet, keep her that way.

Modified Henrys just don't bring the money you would need for them. Sell
her and go buy a 5K if you want a 5K.

Actually an AL-1200 - AL-1500 makes a better transformation to dual tubes.
Build an external PS, drop in a different filament xfmr and run a
conservative 2500-3KW. If caps start flying apart there's enough room to
wheel in Vacuum variables.

But really if you want to build an amp, build one. Start her from scratch
and the $900-$2000 you spend in scrapping out and modifying a factory low
power will go a long ways in building a big gun...

For instance I have a "KIT" right here that'd get you big poop started for
right around the price of a used AL-1500.

BOB DD