I knew after we got past the comments about how it wouldn't work, someone would have some good ideas. Thanks!

-Jim

In particular microwaves operate at 2.4GHz, the resonant frequency of water molecules. Anything with water in it will heat in a microwave.

-Jim

A piece of tape on that single diode is a good idea if you ever want to reinstall it again. You can find it a lot easier with a handle on it.

-Jim

My Swan 400 sweep tube rig with 12V power supply and mobile VFO could probably be had for a song at a swap and it will get you 200W+ out barefoot.

Of course it is a little on the large side...

-Jim

I have an IC-706MKIIG and a screwdriver antenna. I end up with rental cars for 5 days to two weeks and would like to do some HF. Any suggestions on install shortcuts that are still reasonable?

One I have considered is using my Diamond K400 trunk lip mount (holds a small screwdriver surprisingly well!) and clipping a good braided ground lead from the mount down under the car to the front bumper as a quick but possibly effective counterpoise.

Another is renting large GM cars with the battery under the back seat (just lift the cushion) for easy, short battery connections.

Any other ideas?

-Jim

Everything I have purchased from MFJ has been "Mighty Fine Junk". Mobile antennae that work great, but for 1/3 price and the life as a Diamond for example. Lots of small connectors made cheaply. A knock off of the K-400 mobile mount that looks the same but bends easily even though it is "Heavy Duty".

I like their stuff fine, but in the case of MFJ I have found you get what you pay for IMO.

-Jim

I really don't know any hams or non-hams who eat healthy food.

Everything but the veggies is quite dead, and not healthy at all. The fruits & veggies are often still alive, but not really healthy being pulled out of the ground and often skinned.



-Jim

If your charger can keep up with your use and you do not get a hum, it is ok to use a car battery (it acts like a GIANT capacitor on the battery charger output).

If you discharge the battery very low (because the charger cannot keep up) it will shorten its life. If you want to use it this way get a deep cycle battery.

I run a portable jump start battery in the shack as the power supply for my main HF rig with a trickle charger on it. Works great and I have a charged up emergency power source as well.

-Jim

Similar performance flipping from one to the other routed on about the same path. For grins I hooked them in series making a large, 2 turn loop. Worked considerable better than either.

Goes back to that old rule, "more antenna is better".

-Jim

Good advice - the next step will be insulated wire and back to back tests.

I am new to loops but the loop plus the tuner seems very versitile, tuning up at least on 160 through 6m.

-Jim

Your cat5 (cat5e or cat6 is better) is designed to work with ethernet cards and use differential signaling. The many twists and ethernet signaling circuitry likely make it pretty immune to shack RF. But it is still good to avoid running cables you do not want to interact with each other in parallel.

-Jim

Make sure you get one with silicone in it. There are a lot of cleaners that will clean, or lubes that will evaporate over time. But you need a long term lube in there.

-Jim

Interesting! The flagpole I was looking at has an insulated base. I had not considered a gamma match and a real grounded flagpole.

Got the $179 autotuner and it is really plug and play. Makes experimenting easy and turns almost any chunk of wire into a functional antenna without wasting all the energy on heating the coax.

-Jim

A general HF loop size is 8-10 turns 8 inches in diameter though in can vary with cable types and which bands you are on a lot.

-Jim

I've never read anything really good on the subject of keeping the antenna conductor away from nearby objects beyond the basics. The basics I have seen are that the antenna obviously has high current and/or volatges along it and you want to keep it in the open as much as possible, away from people and conductors.

My experience so far has been limited to dipole variations secured at the ends with normal insulators, yagis & log periodics, and verticals.

I am playing with an indoor loop in the attic, using uninsulated aluminum electric fence wire. To start I loosely set up wire along the wood rafters and touching the non-conducting insulation. As expected it performed poorly. But then I got to thinking, why does uninsulated wire touching insulators perform worse? My guess is that it is because the wood and insulation are not as good insulators as ceramic, and there is a lot more contact area. Detuning the antenna is not a problem since it is a random loop with an auto-tuner at the feed point. I think signal bleed off is more the issue but would like to know more.

Next I tightened up the antenna and suspended it so that it is touching at only 6 points other than free space. The stand offs are only nylon cord so they are still not high quality, but there is a lot less area touching at least. Better performance, especially on 20 M (the loop is about 80 feet in length).

I am curious whether it is worth moving to better insulators. At some point I will probably go to an outside design for the loop but the attic design makes it easier to experiment.

I am also curious as to whether I would do better with insulated wire given the multiple contact points. I have used insulated wires for dipoles and they seemed to work about as well after compensating for the length shift.

-Jim