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
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