The AM Forum

Had a big storm here last night.  Lots of rain and very high winds. I was waiting for the wires to come down. THis morning I went out to check.  I did not however, Check the open wire line. 

While talking on the T368 at full tilt on 40 meters today I had crap out.  I noticed the tuning changed on the matchbox. I went outside to inspect the antenna. I found that the storm ripped a metal screen off the window and toss it across my open wire line!  That screen and wire was torched. I had to rip it off the melted insulation.  Everything survived this, I am on the air at full power right now. I need to now replace a section of open wire line.... though.

C

Whew!

I've done that a few time too - noticed the settings of the tuner (or transmitter) were different than normal but didn't put 2 and 2 together and realize something had changed with the antenna system. Err...... 


It usually didn't end well.  ;D

Unless the zap seriously etched into the wire, enough to take out a substantial amount of copper, I wouldn't worry about replacing the zorched section of the feeders. Splices will degrade the integrity of the wire conductor far more than would superficial zorch marks.

back when I had a horizontal loop up and fed with ladder line I used the kind of bal. tuner that has a choke on the low Z input.

That thing needed to be retuned a bit every single time I went to operate.   There was one time when the darndest thing happened.  for about two weeks I'd go and tune the tuner using a swr analyzer in its input and I'd never be able to get a match down to 1:1 on 75 meters.  What the heck.  I'd go outside even in the dark with a flash light and look all around and not see anything amiss.  But I'd put power into it from the rig and see no reflected power.   Over a period of several days I noticed in the daytime it would be okay but every night I'd see the same thing:  swr on the analyzer no lower than around 1.3:1 but it would be flat when I transmitted.  I noticed at night spiders would come out and make webs on the feedline.  I speculated the webs would get wet with dew and do some detuning but I didn't like that idea but I could not come up with anything else obvious. 

After about two weeks I finally figured it out.  At night there was this awful power line noise I would have to null out and it would be gone in the daytime.  The line noise was around 30 dB over S9.  It was strong enough on 75 to induce current in the loop and throw off the swr analyzer but of course had no affect on the transmitter.   I guessed in the daytime the line hardware would heat up enough to expand and close an arc gap somewhere.  The problems (both tuning and noise) went away after the City electric department had a crew come and replace a cracked lightning arrestor on top of one of the poles near my QTH.

However, the tuner would still migrate between use.   that all came to an end when I went to the KW Matchbox last year with the link.  I'll never go back to a non-link coupled balanced network again.  the MB exhibits a 50 ohm Z for days on end.

I retune my Fugly about twice a year on 160. Once when the leaves come out and the other when the leaves fall off the trees. I suspect you had a bad component rather than a bad design. It makes exactly the same feeder current as the KW match box.

I've put the blush on tube finals before engaging brain...   :o

Brings new meaning to the term "Smoke Signals" !

I'll have to watch for the change in tuna behavior with my diaperpole when the leaves drop. This will be the first Fall season w/ the new Tenna.
                                          D.

^^^Now THAT'S what I call a strappin' signal!^^^

 ;D

Maybe I will just wrap the wire with tape and call it good. It just melted the insulation.  The wire is still 100%.  What a close call.  Good ole T3 took it in stride.  The T3 has plate current Trip adjustments on it. I load at 250. When it got up to 330, it simply flipped the breaker and turned it self off :)

C

you know when there is enough fire in the wire when it lets smoke out of the antenna.

Smoke signals???
Must have a new target audience ::)

That would be CW unless someone figures out how to modulate smoke and then there is the issue of demodulation.
Really big news a really big fire.
Half A$$ fire would be SSB

Or try some of that liquid tape or cold shink. It will keep out the water much mo betta.

That reminds me.. I have a roll of coax seal tape here..  Thanks.. I will use that.

C