-----Original Message-----
From: Jim Hargrave [mailto:w5ifp@gvtc.com]
Sent: Saturday, January 3, 2015 9:08 AM
To: 'Tom Osborne'
Subject: RE: [TowerTalk] Tuner SWR won't stay down
Tom,
Have you replaced the 1N34 diodes?
Does the forward power meter change or just the reflected meter.
73, Jim – w5ifp@gvtc.com
>> -----Original Message-----
>> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf
>> Of Tom Osborne
>> Sent: Friday, January 2, 2015 11:11 AM
>> To: towertalk@contesting.com
>> Subject: Re: [TowerTalk] Tuner SWR won't stay down
>>
>> I have 7 antennas here. It will drift on every antenna.
>>
>> There seems to be some confusion on my first posting. This is what I
>> asked:
>>
>> "Hi
>>
>> I picked up an MFJ-989C tuner that has a problem (don't want to hear
>> about 'mitey fine junk).
>>
>> The problem is that the SWR goes down and then slowly creeps back up.
>>
>> I got a new roller inductor and installed it and the SWR still
>> doesn't stay low, even at low power.
>>
>> I took the roller inductor out and put in a switch/coil combo to
>> eliminate the coil problem. SWR still climbs up.
>>
>> Bypassed the SWR circuitry and ran the input from the antenna
>> directly to the capacitor. Still won't stay low.
>>
>> I thought it might be the SWR circuitry but I put another tuner in
>> front of this one and when I tune the SWR down with the other tuner,
>> it stays down, so don't think it should be the SWR circuit.
>>
>> This really has me puzzled. Can't see anything left to check. Any
>> ideas? Thanks and 73 Tom W7WHY "
>>
>> I would think the fact that I can tune the SWR down and it stays down
>> with the other tuner would mean the jumpers and coax are all OK as
>> the 2 tuners are in series with each other. There is definitely a
>> problem with the bad tuner, but just can't figure it out.
>>
>> But - I did put the output of the tuner into the dummy load and it
>> still drifts at low power. Maybe it's time to strip out the parts
>> and build it into something else :-)
>>
>> One last thing I'm gonna try is borrow one of those heat sensors from
>> a friend of mine and shoot it at all the components and see what is
>> heating up. It has to be that what is causing the problem. 73 and
>> appreciate all the suggestions.
>> Tom W7WHY
>>
>>
>> On 1/1/2015 10:10 PM, Jim Thomson wrote:
>> > Date: Thu, 1 Jan 2015 18:56:58 -0600
>> > From: "Bill Aycock" <billaycock@mediacombb.net>
>> > To: "Charles Farr" <cefarr@hughes.net>,
>> <towertalk@contesting.com>
>> > Subject: Re: [TowerTalk] Tuner SWR won't stay down
>> >
>> > I'm puzzled that no one has mentioned the FIRST and most
>> helpful
>> > trouble shooting test-- substituting a dummy load for the
>> antenna.
>> > Bill—W4BSG
>> >
>> > ## agreed ! We don’t even know what ant he is using. Is it a
>> yagi, or
>> > an OCF dipole, or is it a dipole fed with open wire line, OR coax.
>> > What band or bandS does it drift on. Do you have some kind of
>> > defective balun at the feedpoint of the ant ??
>> >
>> > ## Since it drifts, even with low power, you gotta real problem.
>> >
>> > ## Run ONE good coax, directly from the output of the tuner....
>> to a dummy load.
>> > Don’t even mess with a wattmeter, or anything else between
>> output of
>> > tuner and input of dummy load.
>> >
>> > ## Then try and.... match the dummy load..and do it on every
>> band, IF
>> > it doesn’t drift, your tuner is not the issue.
>> >
>> > ##If it does still drift, the tuner is the problem.
>> >
>> > Jim VE7RF
>> >
>> >
>> > _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>>
>> _______________________________________________
>>
>>
>>
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