I'm looking for the inductance and current rating of the HQ-180A power
supply choke so I can find a suitable replacement. Mine burnt to a crisp
although it still shows continuity. It reads about 250 ohms and on the
DMM's Lx function it says 7.0 Hy. Thanks for any help.

"Jack" wrote in message
...
I'm looking for the inductance and current rating of the HQ-180A power
supply choke so I can find a suitable replacement. Mine burnt to a crisp
although it still shows continuity. It reads about 250 ohms and on the
DMM's Lx function it says 7.0 Hy. Thanks for any help.


I see that Peter Dahl has the specifications for the HQ-180A power
transformer
http://www.pwdahl.com/dahlcatalog/hamtrans011404.html#H

HAMMARLUND HQ-180A POWER
REPLACES P/N P26305-1, 115 VAC PRI ONLY
CORE) EI-125 X 1.75 STYLE #) 06 E-I LAMINATED CORE
PR) 115 VAC 60 HZ 1 PH

S1) 420 VCT @ 200 MA CCS

S2) 6.3 VAC @ 6A CCS

DM) HT = 2.625 WT = 3.750 DT = 3.125 MD = 2.500 MW = 3.125
PRICE) $125.00 Plus S&H FOB El Paso, TX WEIGHT) 6 LBS
================
He may also have the filter choke specifications. IF you have the
original -- they will rework / rebuild it -- to keep size, etc.

gb

The filter choke you measured sounds like what the original would be. These
things are not critical at all. Find one about 7 or more henrys and 250 to
300 ohms, and if it is the right size, you are in luck.

Your choke may be fine. Find out the reason it did that. Too much current
was obviously drawn. The fuse should have blown before the choke burning
up.

Check the rectifier and filter cap. Then measure the current draw of the
radio. It would be about 150 to 200 ma.

73, Colin K7FM

Thanks, gb and Colin for the tips. My guess at about 200 mA is ok, I guess.
The choke is pretty charred... all the varnish was boiled out and dried on
the chassis. The outside paper is brittle now. The filter caps seem ok. I
checked them last night and they have between 35 and 50 microamps leakage at
full charge and working voltage. Today I will wire the choke back in and
use a Variac to check for abnormal current draw. I'm not discounting a
shorted turn or two inside the choke although the dc resistance seems
normal. I did just buy a 10H, 300mA choke on Ebay with about the same form
factor.

The power supply filter is the classic pi with 40uf input and 80uf (!)
output. That capacitance combined with 7 Hy sure doesn't seem anywhere near
120Hz for filtering. But what do I know? Thanks again.

Jack

"Jack" wrote in message
...
I'm looking for the inductance and current rating of the HQ-180A power
supply choke so I can find a suitable replacement. Mine burnt to a crisp
although it still shows continuity. It reads about 250 ohms and on the
DMM's Lx function it says 7.0 Hy. Thanks for any help.

The first filter choke for the old Hammarlund SP400 (pp 6F6 output in an 18
tube set) is shown as 150 ma. @ 150 ohms with 12 henries if that eases your
possible anxiety. VE7AFN.


"Jack" wrote in message
...
Thanks, gb and Colin for the tips. My guess at about 200 mA is ok, I guess.
The choke is pretty charred... all the varnish was boiled out and dried on
the chassis. The outside paper is brittle now. The filter caps seem ok. I
checked them last night and they have between 35 and 50 microamps leakage at
full charge and working voltage. Today I will wire the choke back in and
use a Variac to check for abnormal current draw. I'm not discounting a
shorted turn or two inside the choke although the dc resistance seems
normal. I did just buy a 10H, 300mA choke on Ebay with about the same form
factor.

The power supply filter is the classic pi with 40uf input and 80uf (!)
output. That capacitance combined with 7 Hy sure doesn't seem anywhere near
120Hz for filtering. But what do I know? Thanks again.

Jack

"Jack" wrote in message
...
I'm looking for the inductance and current rating of the HQ-180A power
supply choke so I can find a suitable replacement. Mine burnt to a crisp
although it still shows continuity. It reads about 250 ohms and on the
DMM's Lx function it says 7.0 Hy. Thanks for any help.