Last nite I buttoned up the HQ-160 and decided to apply power to a dusty HX-50
SSB exciter. Seems OK so far. The previous owner has wired in SS diodes to
replace the 5R4 or 5V4 tube, and someone left a GT-style 100 KC cal xtal in
that socket -- yes, I found it before powering up.

So far I've read a little cathode current on the meter, which goes down when I
adjust the rear apron bias control. And I can hear the VFO on a nearby rx --
calibration seems good. Both sets of cords are OK -- man, that bandswitch cord
system is scary, more so than the Viking II's loading control.

Now that I've already done the stupid thing of powering up without reforming
the caps (assuming I really do have B+ in the beast and not just bias and LV
supplies?), does anyone have any hints or comments about this rig? Quality,
value, things to look out for, gotchas?

Such as, which mode position is best for initial tune-up into a dummy load?
CW? Nice to have a Drive control so I can start small on power levels.

Might take me a while to find a mic connector (I think every TX maker wanted
to sell his own line of mikes -- no two connectors alike).

73, Mike K. AA1UK

Oscar loves trash, but hates Spam! Delete him to reply to me.

Mike Knudsen wrote:


Now that I've already done the stupid thing of powering up without reforming
the caps (assuming I really do have B+ in the beast and not just bias and LV
supplies?), does anyone have any hints or comments about this rig? Quality,
value, things to look out for, gotchas?

Such as, which mode position is best for initial tune-up into a dummy load?
CW? Nice to have a Drive control so I can start small on power levels.

Might take me a while to find a mic connector (I think every TX maker wanted
to sell his own line of mikes -- no two connectors alike).

73, Mike K. AA1UK

I had one many, many years ago and it was a good rig. I seemed to have
a persistent problem with popping diodes in the bias supply but that may
have been 'my' problem.
Mine had a regular Amphenol mic connector - dunno if that was original
but I didn't need PTT anyway :-)
I wound up changing to 6146 just for the heck of it...no real difference.
It tunes up easy...assuming its neutralized just tune for max output.
You really can't tune it up wrong. I recall it being persnikety about
the 6AW8 and 12BY7 (I think they were) having the tube shields firmly in
place - not unexpected.

-Bill M

In article , - - Bill - -
writes:

had one many, many years ago and it was a good rig. I seemed to have
a persistent problem with popping diodes in the bias supply but that may
have been 'my' problem.

I think mine has the original bias supply diode. I measured the bias voltage
and it adjusts over a wide range.

I *did* find out that the other diodes in there were just replacements for the
low-voltage B+ supply, 375V or so. Four diodes in series-parallel. No idea
what the original was, other than Moore's book entry.

Will have to go up in my attic and break into the Rectifiers box to hunt up a
5R4. No wonder the wiring was intact around the socket. I guess the cathode
current I was reading was just screen current plus grid drive.

Mine had a regular Amphenol mic connector - dunno if that was original
but I didn't need PTT anyway :-)

Mine is what you'd probably call a single-pin Amphenol -- a big screw ring with
a hot contact in the center. I have some signal generator probes like that.
(The real problem is with my Ranger, whose Amphenol has two hot pins inside the
screw circule, one for PTT as you said).

With all the adjustments provided, the VOX inthe HX-50 should work well. It's
nice that it has a built-in antenna relay -- would be a nice match with my
HQ-160 or 180 (though I'd rather use the 180 for AM).

BTW, who designed that function switch -- you have to go thru the MOX (on)
postion to get from STDY to TUNE (CAL). Not the first nor last poorly laid out
rotary switch, but darn, this is a Hammarlund...

I wound up changing to 6146 just for the heck of it...no real difference.
It tunes up easy...assuming its neutralized just tune for max output.

Glad to hear that a 6146 drops in. I was thinking the 6DQ6 in there was a
seep tube, but the power trans' AC is over 800V and sweep tubes are usually
lower, IIRC.

But the 6146 pinouts and heater voltage will match OK?

I haven't cracked the PA cage yet (did Hammarlund own their own screw factory?)
but I trust there's a neatralizing cap in there.

What's the purpose of the nice air trimmer cap in the relay compartment below
the PA?

You really can't tune it up wrong. I recall it being persnikety about
the 6AW8 and 12BY7 (I think they were) having the tube shields firmly in
place - not unexpected.

Well I know I'm getting drive thru those -- turning up the Drive draws more
(screen) current in the PA. The shields are pretty rusty, but I have some
spares handy. Drive tuning is broadband per band, so assuming the coil slugs
are set right for each band, you are right, the tune-up should be easy.

Some rigs (like Viking II or KWM-2) are really paranoid about drawing too much
grid current, especially when tuning up without PA B+ applied. The HX-50
doesn't even have a grid current mode on the meter, so maybe this is less of a
concern?

Tnx and will keep you informed -- Mike K. AA1UK

Oscar loves trash, but hates Spam! Delete him to reply to me.

Mike Knudsen wrote:

Glad to hear that a 6146 drops in. I was thinking the 6DQ6 in there was a
seep tube, but the power trans' AC is over 800V and sweep tubes are usually
lower, IIRC.

But the 6146 pinouts and heater voltage will match OK?

Hi, Mike

The 6DQ5 (not a 6DQ6) and the 6146 have different pinouts -
Bill only meant that he rewired the octal socket to take a 6146
instead of a 6DQ5.

73,
Ed

Mike Knudsen wrote:

With all the adjustments provided, the VOX inthe HX-50 should work well. It's
nice that it has a built-in antenna relay -- would be a nice match with my
HQ-160 or 180 (though I'd rather use the 180 for AM).

I found the VOX to be pretty decent for an old rig. Of course mine
wasn't an 'old' rig at the time :-)


But the 6146 pinouts and heater voltage will match OK?

Rewire the socket. No biggie. But I'm not recommending this. The
power out of the 6146 was less...its that they were cheaper than the
6BQ6 which didn't hold up all that well. Now its a 'rare' vintage rig
and I wouldn't hose it up.


I haven't cracked the PA cage yet (did Hammarlund own their own screw factory?)
but I trust there's a neatralizing cap in there.

Yes.

What's the purpose of the nice air trimmer cap in the relay compartment below
the PA?

Don't recall...is it the neutralizing cap?



Some rigs (like Viking II or KWM-2) are really paranoid about drawing too much
grid current, especially when tuning up without PA B+ applied. The HX-50
doesn't even have a grid current mode on the meter, so maybe this is less of a
concern?

I don't think you CAN draw excessive grid current with it!


-Bill

- - Bill - - wrote:

6BQ6 which didn't hold up all that well.

Ooops,
6DQ5 neither
:-)

-BM

In article , - - Bill - -
writes:

had one many, many years ago and it was a good rig. I seemed to have
a persistent problem with popping diodes in the bias supply but that may
have been 'my' problem.

I think mine has the original bias supply diode. I measured the bias voltage
and it adjusts over a wide range.

I *did* find out that the other diodes in there were just replacements for the
low-voltage B+ supply, 375V or so. Four diodes in series-parallel. No idea
what the original was, other than Moore's book entry.

Will have to go up in my attic and break into the Rectifiers box to hunt up a
5R4. No wonder the wiring was intact around the socket. I guess the cathode
current I was reading was just screen current plus grid drive.

Mine had a regular Amphenol mic connector - dunno if that was original
but I didn't need PTT anyway :-)

Mine is what you'd probably call a single-pin Amphenol -- a big screw ring with
a hot contact in the center. I have some signal generator probes like that.
(The real problem is with my Ranger, whose Amphenol has two hot pins inside the
screw circule, one for PTT as you said).

With all the adjustments provided, the VOX inthe HX-50 should work well. It's
nice that it has a built-in antenna relay -- would be a nice match with my
HQ-160 or 180 (though I'd rather use the 180 for AM).

BTW, who designed that function switch -- you have to go thru the MOX (on)
postion to get from STDY to TUNE (CAL). Not the first nor last poorly laid out
rotary switch, but darn, this is a Hammarlund...

I wound up changing to 6146 just for the heck of it...no real difference.
It tunes up easy...assuming its neutralized just tune for max output.

Glad to hear that a 6146 drops in. I was thinking the 6DQ6 in there was a
seep tube, but the power trans' AC is over 800V and sweep tubes are usually
lower, IIRC.

But the 6146 pinouts and heater voltage will match OK?

I haven't cracked the PA cage yet (did Hammarlund own their own screw factory?)
but I trust there's a neatralizing cap in there.

What's the purpose of the nice air trimmer cap in the relay compartment below
the PA?

You really can't tune it up wrong. I recall it being persnikety about
the 6AW8 and 12BY7 (I think they were) having the tube shields firmly in
place - not unexpected.

Well I know I'm getting drive thru those -- turning up the Drive draws more
(screen) current in the PA. The shields are pretty rusty, but I have some
spares handy. Drive tuning is broadband per band, so assuming the coil slugs
are set right for each band, you are right, the tune-up should be easy.

Some rigs (like Viking II or KWM-2) are really paranoid about drawing too much
grid current, especially when tuning up without PA B+ applied. The HX-50
doesn't even have a grid current mode on the meter, so maybe this is less of a
concern?

Tnx and will keep you informed -- Mike K. AA1UK

Oscar loves trash, but hates Spam! Delete him to reply to me.

Well, I found a nice mil/industrial 5R4WGB tube (with special plastic base that
covers up part of the tube), and also DLed the HX-50 manual from BAMA.

Very helpful to know the bias setting (50-60 mA) and how much cathode current
you dare load up (wow, 180 mA, that's a lot, given that a 6146 tops out at 150
-- however, the plate voltage allegedly drops to 600V).

Also that the little knob under hte PA on the relay compartment really is the
neutralizing cap. Beats reaching between the "hot" finals with a screwdriver,
like in those high-priced Iowa rigs.

Everything seems to work, except no modulation on SSB or AM -- that is, no
increase in RF out or DC in when I zap the mic center pin with a screwdriver,
with the AF gain turned full up. Hope that compactron isn't dead in one
section. Audio circuit should be easy to troubleshoot, especially since that
portion of the BAMA schematic is actually readable (there is a section with the
ghost of a tube just floating in space, with traces of wires and components
around it). If I need a better schematic copy, I'll ask.

Tnx for the discussion so far -- Mike K. AA1UK

Oscar loves trash, but hates Spam! Delete him to reply to me.

Mike Knudsen wrote:


Everything seems to work, except no modulation on SSB or AM -- that is, no
increase in RF out or DC in when I zap the mic center pin with a screwdriver,
with the AF gain turned full up. Hope that compactron isn't dead in one
section. Audio circuit should be easy to troubleshoot,

FWIW, the audio section didn't seem particularly hot in my recollection.
I ran a "piremac" (CB jargon-haha) amplified D-104 with good results
and about 9-10 o'clock in the gain. With any un-amplified mike needed
it to go waay up in my case.

-BM

Well, I found a nice mil/industrial 5R4WGB tube (with special plastic base that
covers up part of the tube), and also DLed the HX-50 manual from BAMA.

Very helpful to know the bias setting (50-60 mA) and how much cathode current
you dare load up (wow, 180 mA, that's a lot, given that a 6146 tops out at 150
-- however, the plate voltage allegedly drops to 600V).

Also that the little knob under hte PA on the relay compartment really is the
neutralizing cap. Beats reaching between the "hot" finals with a screwdriver,
like in those high-priced Iowa rigs.

Everything seems to work, except no modulation on SSB or AM -- that is, no
increase in RF out or DC in when I zap the mic center pin with a screwdriver,
with the AF gain turned full up. Hope that compactron isn't dead in one
section. Audio circuit should be easy to troubleshoot, especially since that
portion of the BAMA schematic is actually readable (there is a section with the
ghost of a tube just floating in space, with traces of wires and components
around it). If I need a better schematic copy, I'll ask.

Tnx for the discussion so far -- Mike K. AA1UK

Oscar loves trash, but hates Spam! Delete him to reply to me.