How about using an NE-2 neon bulb as an RF sniffer?
73,
Bob WB2VUF
Bill Miner wrote:
> Natan and All,
>
> The small wheel on the roller inductor comes from Ten-Tec with some black
> conductive lubricant. If you do not replace the lubricant after cleaning
> you may experience problems from wear later on.
>
> F Y I even though I have been licensed just as long and love boat anchor
> equipment I do NOT use a pencil to check for RF and have not done so since I
> last had on old ARC-5 transmitter on the air. Safety First!
>
> 73, Bill
> ----- Original Message -----
> From: "Natan Huffman" <W6XR@Frontiernet.net>
> To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
> Sent: Wednesday, July 14, 2010 4:38 PM
> Subject: [TenTec] 238B Tuner problems
>
>
>> Dear Friends,
>>
>> Today, I resolved a problem encountered with my Ten Tec 238B antenna
>> tuner.
>> A week ago, my 238 started to misbehave and presented with what appeared
>> as
>> an "open" in the tuner. No discernable flash over had taken place as the
>> problem appeared spontaneously without any noise, smell or any indication
>> trouble was brewing. The VSWR meter stopped working and no RF was getting
>> through to my Array Solutions Power Master residing after the tuner in the
>> RF chain.
>>
>> This morning a telephone call to John at mother Ten Tec ended up with
>> instructions to send it home to be subjected to proper trouble shooting,
>> however, to do that would involve being off the air for longer than what I
>> wanted to be. Therefore one last attempt to ascertain the problem and at
>> Ten Tec Johns suggestion, I inspected all the wafers on the switches
>> inside.
>> All the tabs were there and none showed wear at all. Finally, I became
>> suspicious of just where the RF was going because using my #2 lead pencil
>> I
>> could see it certainly was not getting to the output SO239 as it should.
>> It
>> was easy to draw a spark up to the roller at the variable inductor but no
>> spark at all anywhere on the body of the inductor. The wire wrapping
>> around
>> the inductor body was void of any corrosion or flash indication.
>>
>> Having nothing to loose, I grabbed the can of contact cleaner and doused
>> both the wheel and all the wire on the inductor form. While still damp, a
>> cotton cloth was used to wipe off the excess contact cleaner. My
>> suspicion
>> was confirmed as after the cleaning of the inductor and its little wheel,
>> all was well. It became easy to get a 100 watt spark with the lead pencil
>> on the body of the inductor, the VSWR meter started working and the Power
>> Master showed RF just the way it should. A few hours post, the 238 is
>> doing
>> everything it used to do prior to becoming symptomatic.
>>
>> I suppose the moral here is to clean the inductor and its little wheel
>> because even if it looks clean, enough crud does form to insulate the
>> wheel
>> from the wire on the form. Perhaps others have found this same problem
>> before. It's very nice to avoid a trip to mother Ten Tec and its
>> associated
>> cost and inconvenience. Using a wooden lead pencil for RF sniffing is
>> only
>> allowed if you are into boat anchors and have been licensed over 40 years.
>> A mechanical pencil's use can be downright dangerous so only use a wooden
>> #2!
>>
>> 73
>>
>> Natan W6XR
>> Freeville, NY
>>
>>
>> _______________________________________________
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>> TenTec@contesting.com
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>
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