The AM Forum

 Well, I was going to get on here and say: "I've got my SWR down to 1.4:1 at 100 W carrier without a tuna!" But I must have bumped something because it's sky high again, 5:1.

  The only thing special inline is an ugly balun and I added a few coat hangers. I had to lengthen the antennas about 4 inches to get them resonant on 3885. 3880, and 3875 were also within 2:1 range with a tuna.

 I don't know what I did. It must have been so fragile that even bumping it threw it off again. I did go outside on the balcony to see who was setting off fireworks. That's all I can think of that might have done something.

 The good news is the choke is doing it's job because the transmitter is not hot when I key up, and there is no buzzing in the computer speakers. So the common mode is gone.
 
 I bought a SARK100 antenna analyzer on ebay for $90 and it paid for itself today. It took all day but I managed to get the SWR down so in spite of tonights little set back, I am very happy, a little more work tomorrow and hopefully I'll have something a little more stable.

 I still have to get longer coax so I can route it differently and avoid kicking it if I walk out the door. Right now it's only about 20ft of coax. I would like more so I can at least close the door most of the way.

 Hope is in the air!

A bad or loose center contact in an SO-239 caused me many troubles intermittently.

Same here in an ell. That center pin is actually screwed in and actually has a little hex at its base to do it!

Um, also an instantaneous 1.4:1 SWR could be caused by a short that just as suddenly went away. In your case, Hope not.

I'm assuming you're using coax feed.  1.4:1 is not unusual.  I get 1.2:1 and even 1:1 (depending on frequency) with coax feed most of the time, unless I go very far from the center frequency of the antenna.  For instance, at 3885, it's about 1.3:1.  On 3820 it's close to 1:1.  On 3700 it's back up to around 1.5:1.  So, it is definitely possible to achieve a good match and over a fairly wide frequency range with coax feed.  Multi-band operating is achieved by using the "fan" approach - more than one dipole on the same feedline.

Oh, I decouple the coax from the antenna by running the coax through 20 type 43 ferrite cores at the feedpoint.  Works well !  Do the same thing at Rattlesnake Island.

Regards,  Steve

Here's my antenna. (I take the lanterns down when I try to operate or tune the antenna.)

So Randy, what did you find?
Fixed and steady?

 Not yet. I haven't had the chance to fool with it again. I'll fiddle with it this weekend and see what I can get out of it. If I got a good reading off of it before I'm sure I can do it again. I'll even settle for a tuner 2:1. The most I can tune it down to now is 5:1. I'd just love to know what changed.

 Maybe it's all in my head, but I noticed the noise went down since I installed the choke. I like that. It's still about 3 s-units but that's better than 5! The tone of the noise has also changed. It's no longer electrical sounding (buzzing) it's more of an atmospheric sound (hissing).

Hopefully the 'gain' remained when the noise went but I'd trade 10dB for getting rid of the line noise type buzz any day.

Heck, I'm just glad I don't burn my fingers when I touch the transmitter, or anything else metal attached to it. I got it down to about 3:1 can do more work this weekend.