[TowerTalk] Tuner SWR won't stay down

[Bill Aycock]

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

-----Original Message----- 
From: Charles Farr
Sent: Thursday, January 01, 2015 5:50 PM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Tuner SWR won't stay down

An inexpensive remote reading thermometer, like the one from Harbor
Freight would be a less invasive, and less likely to result in an RF
burn. Sounds like capacitor to me.

Chuck, W6AJW
> Even at low power, large currents can flow in certain components. This 
> sounds like something is heating up and changing value. A giveaway would 
> be if the match drifts faster at high power than at low power. Assuming 
> that's the case, can you get inside and, while running low power, feel 
> around for anything getting warm?
>
> Kim N5OP
>
> "People that make music together cannot be enemies, at least as long as 
> the music lasts." -- Paul Hindemith
>
>> On Jan 1, 2015, at 14:09, Tom Osborne <w7why at frontier.com> wrote:
>>
>> 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
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk 


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com