75m-80m MOBILE ANTENNA - WHAT HAVE YOU MADE?

[Moleculo]

007...are you on the west coast?

CWM,

You story about corona and also moving 5 feet taking the antenna out of resonance hits home with me.

A while back I was sitting in front of the house parked yacking on 75m after a short drive. I was putting 500 watts into my Hi-Q 4" coil with a 3' whip on top. Keep in mind that the base of my antenna is about 4'-5' off the ground, so the total height is about 12.5'. Well, it turns out that the tip of the whip was near some small branches of the tree I was parked next to and I didn't have a decent sized corona ball on it at the time. When my wife came out of the house pointing at my antenna with big wide eyes, I thought she was doing her typical, "you're a big dork with your big ugly antenna" schtick. When I got out of the vehicle, she asked me if I knew that about a foot long blue flame/arc was coming out of my antenna and hitting the tree! Fortunately I didn't damage any equipment, but man I bet my face turned ghost white when she said that!

Eventually I took the whip off and just run around the city with a 18" cap hat 1' above the coil. It was just too touchy on 75/80m with the whip coming close to every tree, sign, etc. and the amp would always kick off because of wild SWR fluctuations. I ran with the cap hat and the whip for a while which worked really well, but it just wasn't practical in the city. Now with just the coil and cap hat I can yack all I want without having swr fluctuation problems. Then when I park, like when I'm camping, I either put the whip back on, or better yet, attach a 12' telescoping whip on it and really talk. Even when I do that, I still leave the cap hat on. It really makes a difference.

 

[CDX-007]

Yeppers, about 45 minutes South of Reno, Nv.

Where didja get the 12' telescoping? I always carry a couple of 61' & 32.5' wires with gator clips on each end so I can stretch them out and clip to a tree branch, rock outcropping, Moose's tail, etc... Really kicks ass on the screwdriver except for certain lower angle DX conditions, but I'm usually on 75m/80m during the later evening calling CQ rag chew, CQ rag chew...

 

[novakor]

CDX-007.............45minutes from south of Reno? What no call AKA: Max i have a new rig, well new to me..........monster rig.
Whatz up with your cell?
CDX-2double8

 

[CDX-007]

Hi Stu, yep, Carson vicinity.

Hey, on the new rig, push 'IF SHIFT' and you'll be about 3kc wide.
Push 'FILTER' and you'll be nice & narrow, (~2kc wide) for those contest weekends when you can find a clear frequency.

Don't let 'MODE-S' scare you, it tells the scan to stay in the mode (USB / LSB / CW / FM) which you are listening to when you hit 'SCAN' and will select only those memory channels which are of the same mode.

Ie: if you are listening to 10m USB and hit 'SCAN' with the 'MODE-S' button selected you'll only scan memories which are in USB.

That screws up a lot of people. The often think their synthesizer is going out.

You're going to be awestruck when it arrives. It's bigger than you are expecting, and the quality of the feel of everythng will make you forget the FT-990 in about a New York Minute, and that's not a lot of time!

Looking forward to our 1st 75m QSO!!! - Get that 120' wire strung, there 'Tough Guy'!

73

 

[C W Morse]

A friend of mine and I had the most trouble with corona on 160 Meters, also running 500+ watts.

I sold a screwdriver to a fella in an adjacent state. He was using it as a base station and used a chain link fence for a counterpoise/ground. He emailed me how well it was doing.
However, just when I thought all was well, he emailed me that he was talking on 40 meters and the SWR mysteriously went bonkers. After a few emails, he finally admitted that he had put the antenna under a tree. It rained when the guy was having trouble and the moisture plus the weight of the water allowed the leaves to "droop" down and touch the whip. With 800 watts, moisture not withstanding, the leaves began to smolder (visibly!), then smoke MORE, then the tree was actually on FIRE! :shock: That was causing the high SWR---and some damage to the antenna.

73

CWM

 

[CDX-007]

It's good to hear there's still guys around getting all fired up about radio!

Major engine repair has had the Suby laid up for a couple of months while I drive the luxury car (read 'gas guzzler') but I'll have it roadwirthy again in a few more weeks then it's antenna time!

Hey Steven, Try 3.840 one of these evenings around 10:30pst. You'll probably hear Tom KE6YNH as he's always running a Tokyo High Power SS kw. That's where I've been landing lately, and I'm hoping I'll have the 1499 watter on-line by then. If not by tomorrow, definitely by Sunday evening. Try the vertical, you'll prolly need the lower angle.

How often do you hear the left coast on the loop? What's their usual RST?

73