Likely the K13 relay contacts are open, due to coil failure, and thus there
is no load on the PA. Therefore it draws very little current until
increased drive causes it to break into oscillation at which time Ic soars.
Normal and as expected. Guys, this is a very simply problem to diagnose and
one that is easy to resolve. Plus it is a common failure mode.
Most likely it is K13 that has an open coil. Just look at the schematic.
If K13 does not close then there is no load on the PA. All other bands work
with output leading one to believe the test conditions are valid. The ALC
LED being on says there's a lot of RF being developed, but not getting to
the output of the LPF as seen by the comparator on the 9 MHz filter board.
This tells the system to reduce TX drive.
One must unsolder the relay an not damage the traces and pads on the PC
board. Otherwise, it is best to send to Paul at Tentec service. That's a
lot cheaper than trying to find a replacement LPF board. Plus a
"repair-it-yourself project" will require one to order the relay anyway.
Last time I spoke with Paul he indicated that he usually has a sack full on
his desk. Relays are inexpensive, labor is not.
73
Bob, K4TAX
----- Original Message -----
From: "Jim Allen" <jim.allen@longhornband.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, August 18, 2014 11:13 AM
Subject: Re: [TenTec] 160 Meter Problem
"As I advance the PWR control, and get on the other side of halfway, there
are occasional spikes on the meter, very short. As the PWR is advanced,
the Ic suddenly jumps from zero to about 10, then increases erratically up
to near 20, with no output on the wattmeter."
73 de W6OGC Jim Allen
On Mon, Aug 18, 2014 at 11:03 AM, Rick - DJ0IP / NJ0IP <Rick@dj0ip.de>
wrote:
OK, so it is transmitting, but just not enough power.
Perhaps my first impulse was indeed correct, a relay on the LPF board.
It just seems to me that it should draw more current in TX, even if the
LPF
isn't properly selected.
How many amps does it appear to be drawing, or can you not tell?
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim
Allen
Sent: Monday, August 18, 2014 5:43 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] 160 Meter Problem
OK, Omni VI+ on Dummy Load, Omni VI on dipole. With no antenna on VI, I
can
barely hear the VI+. With the dipole I hear it loud and clear.
Thanks!
73 de W6OGC Jim Allen
On Mon, Aug 18, 2014 at 10:30 AM, Rick - DJ0IP / NJ0IP <Rick@dj0ip.de>
wrote:
> WAIT, that was a very stupid comment from me.
> If it's not drawing power, then it's not a relay on the LPF board.
>
> Instead, I wonder if it's even transmitting at all on 160m.
> With power turned down low, tune to the same frequency on a second
> receiver and see if you hear any signal.
> To be safe, start with no antenna attached to the second receiver, if
> you hear nothing then add a short piece of wire as an antenna.
> Normally you should hear a 599 signal if it is transmitting at all.
>
> If it is not transmitting, then it might be the local oscillator which
> is a crystal oscillator.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Rick
> - DJ0IP / NJ0IP
> Sent: Monday, August 18, 2014 5:26 PM
> To: 'Discussion of Ten-Tec Equipment'
> Subject: Re: [TenTec] 160 Meter Problem
>
> This sounds like a 160m band relay not functioning on the LPF board.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim
> Allen
> Sent: Monday, August 18, 2014 5:21 PM
> To: n4py3@earthlink.net; Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] 160 Meter Problem
>
> I'm out here in the shack now with the radio to a dummy load. To
> answer Carl's question, no, there was no noticeable change in current
> going from receive to tune. I tune at very low power, just enough to
> make the AH-4 happy, and generally run QRP anyway. When I "tune" now,
> the red "tune" LED illuminates, the green "ALC" illuminates, the audio
> goes away and nothing else. There is no output.
>
> As I advance the PWR control, and get on the other side of halfway,
> there are occasional spikes on the meter, very short. As the PWR is
> advanced, the Ic suddenly jumps from zero to about 10, then increases
> erratically up to near 20, with no output on the wattmeter.
>
> On 80M, as I advance the PWR, the output shown on the wattmeter and
> FWD meter increases smoothly up to 100 watts. Ic advances slowly then
> up to about 16 amps at full power.
>
> On 40, it draws more than 20 amps at full PWR, slightly more than 100
> watts on the wattmeter. On 30M, it draws about 13 amps and gives about
35
watts.
> On 20M, full 100 watts on about 15 amps. Same on 17, except Ic is
> about 18 amps. and the same on 15, 12 and 10M, with some variation in
> Ic between 15 and 18 amps.
>
> Thanks for the suggestions so far. Any ideas?
>
> 73 de W6OGC Jim Allen
>
>
> On Mon, Aug 18, 2014 at 9:36 AM, Carl Moreschi <n4py3@earthlink.net>
> wrote:
>
> > Was the Omni VI drawing lots of current from the power supply when
> > you keyed it on 160?
> >
> > Carl Moreschi N4PY
> > 58 Hogwood Rd
> > Louisburg, NC 27549
> > www.n4py.com
> >
> >
> > On 8/18/2014 10:31 AM, Jim Allen wrote:
> >
> >> The AH-4 actually matches just about anything as long as it is
> >> longer than 7M, the longer the better, but not an even 1/4 wl.
> >> There is a spreadsheet of "forbidden lengths" available in the
> >> Yahoo Groups files section.
> >>
> >> I intend to run the Omni VI+ on a dummy load today, on every band,
> >> but I saw nothing that made me think the match was a problem. I
> >> can imagine seeing a bad load would "fold back" power but there was
> >> nothing
> to fold.
> >>
> >> The 706 matched up just fine, same antenna, same feed line, same
> >> tuner, same connector, etc.
> >>
> >> I'll report back if anything develops.
> >>
> >> 73 de W6OGC Jim Allen
> >>
> >>
> >> On Mon, Aug 18, 2014 at 9:17 AM, Rick - DJ0IP /
> >> NJ0IP<Rick@dj0ip.de>
> >> wrote:
> >>
> >> Start with a dummy load.
> >>> Make sure the Omni VI is working OK on the dummy load.
> >>>
> >>> I'm surprised the AH-4 even found a match.
> >>> It is only rated to cover 80 thru 10m.
> >>> I used an AH-4 a lot in the past but I could never get it to load
> >>> anything up on 160m.
> >>>
> >>> 73 - Rick, DJ0IP
> >>> (Nr. Frankfurt am Main)
> >>>
> >>>
> >>> -----Original Message-----
> >>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
> >>> Jim Allen
> >>> Sent: Monday, August 18, 2014 4:12 PM
> >>> To: Discussion of Ten-Tec Equipment
> >>> Subject: [TenTec] 160 Meter Problem
> >>>
> >>> I was sitting in the shack minding my own business last night when
> >>> I noticed on the DX cluster that W1AW/5 was on 1821.5 in Oklahoma.
> >>> I have not tried 160M here, but do have a 130' dipole and an AH-4
> >>> to match it with, which might work, so I thought, "what the hey?"
> >>>
> >>> I got it all set up and could hear W1AW/5 extraordinarily well. I
> >>> moved up the band a bit to tune and ........ nothing. No output
> >>> whatsoever. I checked... traced the coax, antenna connected to
> >>> wattmeter, wattmeter connected to Omni VI+, AH-4 tune control
> >>> getting power, etc. All seemed to be in order. I tried again...
> >>> nothing. The radio went into tune no output no tone, nothing. I
> >>> switched to 80M, found a clear spot, tuned normally.
> >>> I went back to 160M, nothing. I advanced the power knob from
> >>> nothing to as high as I dared... still nothing.
> >>>
> >>> I then moved to the 706MKIIG, got it going on 160 and made the
> >>> contact, no problem, although I did have to use 100 watts instead
> >>> of 5.
> >>>
> >>> This is the first time I have tried this Omni VI+ on 160M, but it
> >>> seems to be working just fine on the other bands, very well,
> >>> actually.
> >>>
> >>> What could this be? Where should I start?
> >>>
> >>> 73 de W6OGC Jim Allen
> >>> _______________________________________________
> >>> TenTec mailing list
> >>> TenTec@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/tentec
> >>>
> >>> _______________________________________________
> >>> TenTec mailing list
> >>> TenTec@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/tentec
> >>>
> >>> _______________________________________________
> >> TenTec mailing list
> >> TenTec@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/tentec
> >>
> >> _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
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