I recently managed to purchase an unused (Still had the factory test message recorded) TH V5 for a very good price. However, the basic wire antenna mas missing from the box. The realtor I bought it from had another TH and measured the antenna, telling me it was only 24 inches. That didn't sound right, and I found a TH spec sheet online that showed the length to be 3 meters. I also found an i.AM.radio spec sheet online which gave the length 8 feet. Just to be sure (lol), I asked Radio Systems what the TH V5 wire antenna length should be, and was told 3 feet. Although the TH V5 will calibrate using any of those lengths on a high frequency, I believe 3 meters to be the proper length since the TH is 15.219 certified.
For test purposes, I want to use the optimum length indoor wire antenna for 1650 khz before I experiment outdoors using a homebrew loading coil, vertical, and radials.
The correct length is 3 meters, or 9.84252 feet. Under Part 15 operation, TOTAL length of your antenna, feedline, and ground cannot exceed 3 meters. I have several of these, all of which the wire is pre-cut just shy of 10 feet. Hope this helps.
Thanks, I was pretty sure 3 meters was the correct length. Yes, I understand about the total length not exceeding 3 meters. If I experiment with a loading coil and grounded radials bonded to the TH chassis, I'll need to shorten the vertical element accordingly.
It will still auto-tune up to about 18 feet, but to keep legal, you must trim it to 3 meters (including the ground lead).
Last week, I tested the TH at my place of employment. I was not impressed. The signal barely got to the street before it was lost. Knowing that radio reception is poor in that building, I took the TH home and set it up in the attic so it would be elevated. Now, I live in a rural area, but it's not all farms. The main roads surrounding my property form a triangle that has a perimeter of about 1 mile. Using a car radio, the TH signal was audible as I drove triangle. I doubt anyone living within the triangle would be interested in hearing my talking house, but the signal is there. I won't be leaving the TH in the attic because the attic's temperature gets way too hot in the summer. Next, I'll have to setup something quick and easy in the yard away from the house.
Your place of employment might have a lot of concrete wih rebar. If you set up the antenna indoors, the rebar acts like a Faraday Cage, preventing the signal from getting out (or in, for that matter).
What you want to do is set it up as close to outside as possible, wherever you mount it. If you use a ducted fan cooler you might be able to leave it in the attic, near the vents.
Outdoors may mean mounting the unit outdoors too. There are TIS systems which use the TH in a weatherproof box, on a substantial pole, such as a phone pole. You coud find a similar box and put it outside on the end of your house eave, along with the external ATU system, or lay out the wire in a place it will work best. Could even attach it to a PVC pipe with zip ties and nylon guys to stabilize it.
If you look back in the archives, maybe yu can find the post I did on putting it in an arch window inside, got our more than 800' in some directions.
Also, if you can get a good ground, or ground proximity for counterpoise, it will help.
Using the wire antenna, I believe the TH will work best at 1610 kHz if you can, but that is usuallly a fairly busy frequency in many areas. Check the FCC site for researching open freqs in your area.