[AMRadio] ever have one of those days?


W5OMR/Geoff w5omr at satx.rr.com
Fri Oct 28 14:58:31 EDT 2005


First off, had a nice QSO with Tim/WA1HLR on/around 3.885.  I -barely- 
heard Joe/KB5YA announce a couple of times that he was around, got into 
a short IM QSO with Ronnie/W5SUM about his voice being hoarse, head-ache 
and all sinus-y... then worked Tim, then signed at 6am and came in, made 
coffee, breakfast, etc...
Went back out to the shack at around 7am, and was there for the 
'later-morning' crowd.  We had a crowd this morning.
After I signed out, I listened to John/K5FTN and Lum/K5AYD talk about 
Apaches (transmitters, not indians)

I wanted to break in and inject a comment or two, since I was still 
sitting there, but I couldn't.  I had no carrier.  I had just -been- 
talking, what the heck was going on?

I don't know for sure what happened, but I started checking voltages and 
started with the relay in my rig (big 24v contactor) which activates 
when grid drive is applied and applies whatever Primary AC voltage is 
selected with the Vari-AC to the primary of the plate transformers.  The 
relay was still slamming hard, so I thought perhaps there was a bad 
fuse.  Nope, all fuses good. Hmmmm... get the voltmeter out, disconnect 
the DC line from the power supply, turn the Vari-AC down to around 10 or 
so VAC (might have been as much as 20VAC), measured that voltage at the 
relay input, but didn't read anything on the output.  Maybe the meter 
test-leads weren't making good enough contact.  Measured for B+ from the 
power supply, and sure enough, there was around 250VDC!
What the...huh?
After some head-scratching, I measured for AC voltage again at the 
relay, and there was voltage there.  Cool!  I thought I had identified 
the problem.   Yeah, right... Life ain't that simple for me.

I turned around and walked back in front of the rig, and kicked on the 
exciter and then started to adjust the Vari-AC for around 100w of 
carrier out.  20, 40, 50vac on the primary, and no current on the 
Vari-AC.  Hmmmm... 60, 70, 80V - no carrier, no modulator current, no 
nuttin'.  Crap!  There's an intermittent in the relay. I HATES 
intermittents!  At least I thought it was an intermittent, and it's 
possible that might have been the case, but there's more.  There's 
always more, isn't there?

Sooo... I pulled the relay out of the rig, cleaned up the contact points 
as best as I could with a couple of splashes of DeOxIt, and burnishing 
the contact points with a twenny dollar bill, pulled off, scraped the 
wire, and re-attached the AC power cord.  THEN, just to make sure I 
wasn't imagining things, I connected another peice of zip cord with a 
plug on one end to where the transformer primary would connect, and 
'slowly' applied voltage with the Vari-AC.  0v on the primarys, and 0v 
of bias on the modulators,   20v saw some current rise.. 40v saw the 
current rise somemore.  YES! We're drawing current again!  Turned off 
the Vari-AC, re-zeroed the Vari-AC, shut down the exciter, and unplugged 
the AC line out of the Vari-AC and re-installed the now newly 
re-furbished contactor relay.  Connected the output of the relay to the 
extension cord I was using out of the Vari-AC, came back around to the 
front of the rig, kicked on the exciter, turned on the Vari-AC, and 
started to bring it up slowly, looking for current on the Amp Meter 
built into the Vari-AC.

20v, 40v, 50v, and nothing.  "DAMNIT!  WHAT IS IT?" I said loudly to no 
one else in the room.  Shut it all down, walked back behind the rig, and 
then noticed that the extention cord that the relay was plugged into, 
was NOT plugged into the Vari-AC.  I had unplugged it, to plug in the 
peice of zip-cord with a plug on one end.  *sigh*  I was being safe.  
Yeah, that's it - that's the ticket!  I was.. uh...   *(sigh)*  but, 
that's not where the fun stops...

Got the AC line hooked up, everything is now ready, and I kick on the 
exciter, the relay closes, I turn the Vari-AC on (always turned off, 
reduced to 0v, and the cord disconnected before I go behind the rig) 
start to bring up the voltage, and still nothing.  I ain't got much hair 
left... I don't wanna pull out what's left of it...

Kick off the exciter, kill the Vari-AC, turn it to 0V, go behind the 
rig, kick at the multi-outlet strip and .. and... *geeze*  the line cord 
for the filaments of the 3B28's in the powersupply fell out of it's 
socket.  Oh, man...

The whole time I was chasing a problem that I thought was in the relay, 
was just that the plug was loose in the 110vAC socket!  Oh, I coulda 
SCREAMED!
I got my trusty needle nose pliers out, put a little 'bend towards the 
middle' in the two prongs, plugged it back in and now the 3B28's are 
warming to the touch after about 2 mins (before they were cold to the 
touch, and that should have been my first clue, right there), went back, 
fired up, turned on the Vari-AC, turned up the voltage and we're now 
making 200w with 100mA of resting current on the modulators, and all is 
right with the world again.  I didn't think of  "Is it pulgged in?", 
because I had been on the air since 5am, when I started wtih 
Tim/WA1HLR.   You'd think though, that as a ham with 20+ years on the 
air, and being raised around electronics that I would know better.  
C'est la vie!

All of these headaches and hassels could have been avoided if I had just 
checked the AC plugs.  There might be something to solid-stating the 
rectifiers in some of these older rigs.  I think what I'll do instead, 
is to take some 3-conductor pre-made 110v AC lines and connect -them- to 
the power supplies.  This would ensure that the voltage is properly 
phased and any residual hum is therefore eliminated.

What time did I get done?  Well, I signed a little after 9am with the 
group on 3.880 and came back in the house at noon, to watch the news and 
make some breakfast, having just finished up my daily session in the 
hamshack.

Speaking of the group, I was doing some recording this morning and have 
not -yet- manipulated that audio file, but I will convert it to MP3 so 
that it's availalble for download.  I'm first going to burn a CD with 
the raw wave file.  If you're interested in a copy, let me know - I'll 
mail a CD with the full wave file (if I dont find some way to screw 
-that- up, too!) to anyone who sends a Self-Abused Stomped Antelope to 
my address (good at QRZ'ed)

What a morning for AM, though!

Eight hams in the round table from 7am to 9am or so...

WB5PKD, BJ - Willis, TX
W5OMR, Geoff - Poverty Gulch
W5KGZ, Perry - Bevel Oaks, TX (between Sour Lake and Beaumont, TX)
W5DWP, Wayne - Snuff Gully (Vidor, TX)
WA5RNL, Roger - in what's left of Ol' Richmond, TX
WA5FWC, Gary - Venus, TX
K5FTN, John - Medina Lake/Bandera County
and
KD5YHX, Mason in Wiley, TX (or is that Wiley in Mason, TX?)

And no Yogie/KC5MIP?
I miss hearing Steve/K5LTK, King/K5KXF, of course Otis/K5SWK and a few 
others... I wonder if anyone has heard from Stan/W5VMJ, in Victoria?

That's the news that's fit for print from San Antonio.

See you guys (where's the girl-type hams?) on the air, soon.

-- 
73 = Best Regards,
-Geoff/W5OMR







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