Doublet Problems

[n2ize]

Can't seem to tune my doublet ant. Few months ago I got it to tune properly. I might have to pull it down and check the connectors. :(

[KG4CGC]

Yep. I believe it was moisture in the connectors that did in the AT on my 570.
Usually the connectors are the best place to start, but you already knew that. :)

[kf0rt]

Did you get that working, Charles?

[KG4CGC]

Did you get that working, Charles?
Negative. Right now I'm too scared to do surface mount work with my current iron. Once I get that sorted I'll go from there.
Currently I monitor with an FT100 with a fried exciter for SSB, a DX-394 from RS for AM and for 2m the always working, built like a tank, HTX-242.
I'm thinking about dragging out the Hammurlund SP(J) 600. It only weighs in at 125 to 150 pounds. The National SW-54 needs a cap job as they are still all originals.
I also want to add the DX-396 or 400(?) to the que, it's the portable made by Sangean. Great little receiver really but the audio going to the speaker is distorted but if I use headphones or external speaker it's fine.
I also have a bipolar VHF antenna I want to use for all my scanner 2m sideband monitoring needs.
The Zenith TO only gets pulled out for special occasions, birthdays, Christmas etc.

I believe I'll mix all the audio from the receivers into a single stereo unit to improve the dynamic range as I also need more audio when monitoring 2m ssb. I also need more space LOL!

[n2ize]

Okay... it's tuning now. I went outside and yanked on the legs of the antenna a few times. One side was also very slack so I tightened it up a bit. Now I'm able to tune out the swr. There might have been a bunch of wet leaves or something laying on the feed point and throwing the whole thing out of resonance. It's been EXTREMELY wet here. The feed point is about 70 feet up and very hard to see. If I run some real power into it it might make some fireworks up there. :mrgreen: :mrgreen:

Now I just gotta put the Dow Key back in line and I should be able to get on the aire.

[N5RLR]

...Right now I'm too scared to do surface mount work with my current iron. Once I get that sorted I'll go from there...
Take a length of small-gauge solid copper wire, strip and tin, and wrap around your iron's tip with a bit extending past the end. A "needle" iron, if you will. :mrgreen:

Oh, and for us *ahem* getting on in years, a jewelers' loupe that clips to the eyeglasses, helps. :angel

Isn't there an old trick to dipoles, of placing a high-value resistor across the feedpoint, so that any trouble can be detected with an ohmmeter as a change in the resistor's initial value? What value/power rating for (x) transmitter power?

[n0eq]

..The feed point is about 70 feet up and very hard to see.


That's a nice, high dipole. I'd like to hear more, please.
Length? All flattop or inv V/dropped ends etc?
Feedline type (Ladder etc)? Distance to radio?
Any special tricks in getting the feedline into the shack
(assuming your shack is inside)?

http://www.digitalcartography.com/camp/AmatuerRadioResponseVehicle.bmp


Craig 'Lumpy' Lemke

http://www.n0eq.com

[KG4CGC]

...Right now I'm too scared to do surface mount work with my current iron. Once I get that sorted I'll go from there...
Take a length of small-gauge solid copper wire, strip and tin, and wrap around your iron's tip with a bit extending past the end. A "needle" iron, if you will. :mrgreen:

Oh, and for us *ahem* getting on in years, a jewelers' loupe that clips to the eyeglasses, helps. :angel

Thanks. Sound better than my idea of grinding the tip because it's reversible. Got a pair of 1x readers for tight work. Even with 20/15 vision they really sharpen up the lines for small and close up stuff.
I even already have an idea of how to work the wire. Thanks Again. :)

[n2ize]

..The feed point is about 70 feet up and very hard to see.


That's a nice, high dipole. I'd like to hear more, please.
Length? All flattop or inv V/dropped ends etc?
Feedline type (Ladder etc)? Distance to radio?
Any special tricks in getting the feedline into the shack
(assuming your shack is inside)?

http://www.digitalcartography.com/camp/AmatuerRadioResponseVehicle.bmp


Craig 'Lumpy' Lemke

http://www.n0eq.com

Height ... 65-70 ft. thanks to a very tall sycamore tree. An equally tall maple is also on standby should the need for a second support structure arise.

Length ... cut for 80 meters

Style. ... Inverted Vee design. Property is too small to run full length flattop.

Feedline ... Insulated balanced (open wire) line.

Length into shack... approx 70-75 feet. Shack is on 2nd floor so that gives me about 15 feet above ground. Line reaches in with excess to spare.

Point of entry... Currently enters through side louvers on an air conditioner. But soon will enter via feed through insulators in attic window.

Tuner... A Johnson 250 watt link coupled "Matchbox" tuner.

Usable bands... Antenna can be tuned for 75, 40, 20 and even 10 meters. Most efficient on 75 and 40, but pretty good on 20 as well. I have had limited success on 160 meters by tying the ends of the balanced feed line together and running it as a random length wire against a ground. I also almost smoked a network hub trying to run it on 160.
:mrgreen:

Grounding system... heavy gauge braided copper rope tied to buried rod. Good electrical ground... decent RF ground... probably not a good lightning ground. (Hopefully we'll never have to test that last property).

Incidents... Have heard the feed line/tuner arc & crackle during nearby lightening strikes.

[n0eq]

( ...describing his doublet...)

Height ... 65-70 ft...

Length ... cut for 80 meters

Style. ... Inverted Vee design...

Feedline ... Insulated balanced (open wire) line.

Length into shack... approx 70-75 feet. Shack is on 2nd floor...

Point of entry... Currently enters through side louvers on an air conditioner. But soon will enter via feed through insulators in attic window.

Tuner... A Johnson 250 watt link coupled "Matchbox" tuner.

Usable bands... Antenna can be tuned for 75, 40, 20 and even 10 meters. Most efficient on 75 and 40, but pretty good on 20 as well...

Grounding system... heavy gauge braided copper rope tied to buried rod. Good electrical ground... decent RF ground...



It's a beautiful thing, man!

I dig big wire antennas. Simple, tremendously effective, cheap!

http://www.digitalcartography.com/camp/CondomMan.bmp


Craig 'Lumpy' Lemke

http://www.n0eq.com

[n2ize]

Latest issue, One leg of the doublet snapped, apparently struck by a piece of falling tree. I already have a rope spool attached to the support lines ready to lower away as soon as I can attend to the repair job. Also in store is a new center insulator to replace the one that's been suspended in mid-aire for two decades.

[n0eq]

Latest issue, One leg of the doublet snapped, apparently struck by a piece of falling tree...



So, how is it as an end fed 40?


Craig 'Lumpy' Lemke

www.n0eq.com (http://www.n0eq.com)

[n2ize]

Latest issue, One leg of the doublet snapped, apparently struck by a piece of falling tree...



So, how is it as an end fed 40?


Craig 'Lumpy' Lemke

http://www.n0eq.com

It would probably work as such, although I haven't tried it. :)