Lou:
Well, I was on HF all last eevening in the RV with a direct connection to an
AC wall outlet, and had no problem at all either on 20 or 40 meters. I was
doing CW with 100 watts, so I am pretty convinced that the cheap power strip
was the culprit.
Looks like it's time to go out and get a good one like you guys are
suggesting, before Field Day, when I'll be running the HF rig and the laptop
for logging at the same time.
73 from Tom Behler: KB8TYJ
----- Original Message -----
From: "Lou Kline" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, June 06, 2007 8:53 PM
Subject: Re: interesting RFI experience
> Hi Tom.
>
> One thing you might look for is a power strip that has a built in EMI
> filter in addition to surge suppression. But, it sounds like you might
> have a lot of RF flying around in there. Putting some chokes on some of
> the power leads might break that up a little. I haven't heard of an
> interaction that severe since the days when I used to use a random wire
> loaded against a long ground wire (my shack was on the second floor in
> those days). Anyway, I had a Kenwood TR7600 2 meter radio with the RM76
> Microprocessor Control Unit which provided 6 memories and scanning. Hot
> stuff in 1980. And, I was using a Kenwood TS130S for the HF rig. Anyway,
> besides getting enough RF on the controls of the 130S to leave red marks
> on
> my fingers, I managed to very nicely erase the programming on the Kenwood
> 2
> meter radio with it just sitting there on the local repeater while I was
> sending CW on 80 meters! I shudder to think what I probably was getting
> for RF exposure with that setup. It is why I am not a fan of random wires
> for power levels above 5 watts nowadays.
>
> 73, de Lou K2LKK
>
>
>
> At 10:18 AM 6/6/2007 -0400, you wrote:
>>Hi, all.
>>
>>Well, while this latest RFI thread is going on, I'm sitting here waiting
>>for
>>the XYL to come home from her last day of elementary school teaching, when
>>we'll be taking off on our RV trip first to Georgia for a family wedding,
>>and then to Arizona to visit our son.
>>
>>Anyway, a very interesting, and somewhat scary, RFI thing happened to me
>>yesterday while I was testing my HF set-up in the RV for our trip.
>>
>>As background, I have an Icom 718 for HF, and it is connected to a
>>Predator
>>screw-driver antenna on the back lefthand corner of the RV. The radio and
>>antenna are, I believe, thoroughly grounded to a common point on the frame
>>of the RV, since I had this work done by a professional RV tech who is
>>also
>>a ham. In the front of the RV, I have a TMV7A for mobile VHF/UHF use.
>>That
>>rig is connected to a Diamond dual-band mobile antenna that is securely
>>clamped to the top of the ladder on the other side of the back of the RV.
>>
>>Anyway, yesterday, I was doing a test on the CW portion of the 20 meter
>>band, when something incredibly strange happened. My TMV7A mobile rig was
>>totally off, and not being used. ... When I did the HF test, some extra RF
>>must have been floating around, because it turned on the TMV7A, and caused
>>the TMV7A to make all kinds of beeps and boops. In a major state of panic
>>or at least heightened concern, I checked out the TMV7A, and it was
>>totally
>>locked up. ... My memories were still there, but I couldn't do much if
>>anything with the radio. I couldn't even do a re-set using the re-set
>>sequence with the control head which is mounted below the dash board. ...
>>It was funny too, because the speach output would give me the memory
>>number
>>I was on, but wouldn't even read the frequency.
>>
>>Fortunately, I had some instructions from this list which told me how to
>>do
>>a full re-set of the TMV7A using the recessed re-set button on the front
>>of
>>the actual radio unit. I did that, re-programmed the radio, and was back
>>in
>>business.
>>
>>Then, I went into troubleshooting mode, and found what I think was the
>>source of the problem. I disconnected the power supply for the TMV7A from
>>a
>>power strip that I was using, and plugged it more directly into an outlet
>>in
>>the RV via a short extension cord. I tried getting on 20 meters again,
>>where I was before, and had no RFI problem at all.
>>
>>So, I think my problem was in the cheap power strip I was using.
>>
>>Which brings up a question: Anyone know of a good high-quality power
>>strip
>>I might by that has better isolation in it, so this problem won't recur?
>>I'm willing to pay some good money for it, since I don't want stray RF
>>messing with either the TMV7A or any of the other electronics in the RV.
>>
>>I will have periodic e-mail access while we are on our trip, although my
>>responses may be somewhat delayed since we will be on the road quite a
>>bit.
>>Fortunately, though, the camp grounds we will be staying at have internet
>>access.
>>
>>73 from Tom Behler: KB8TYJ, soon to be RV mobile
>>
>>
>>
>>--
>>No virus found in this incoming message.
>>Checked by AVG Free Edition.
>>Version: 7.5.472 / Virus Database: 269.8.11/837 - Release Date: 6/6/2007
>>2:03 PM
>
> Louis Kim Kline
> A.R.S. K2LKK
> Home e-mail: [log in to unmask]
> Work e-mail: [log in to unmask]
> Work Telephone: (585) 697-5753
>
|
