Radio scientists:
I have two long wire ten foot antennas in the attic for two different AM broadcast band transmitters. I have one long wire ten foot antenna mounted outside of the house. Al l antennas are horizontal antennas.
The outside antenna is made from 12 gauge stranded wire and is only about 8 feet off the ground, maybe 9 in one part. All transmitters for each antenna are in the basement.
My home is a one story small rambler, so the antennas in the attic are about 12 feet off the ground at most and they ride close to the peak in the roof. Each antenna has its own loading coil.
Each transmitter is a Talking house 5 and power out of each transmitter as tested comes to about 100Mw. On each transmitter so they all have the same power output.
I have to honestly say the attic antennas work almost better than the one I have mounted outside. No matter if its winter and the roof is covered with snow or summer.
The outside antenna is too close to the ground and has a lot of capacitance but the capacitance cancels out nicely with the loading coil. None of the antennas are actually impedance matched; I just run the signal to the loading coils with RG 59.
The coax is shield is grounded again in the attic and on the outside antenna it is the shield is also reground. So what I am saying both ends of the coax shield is securely grounded at each end.
I run the center lead of the coax into the loading coil and from that into the antenna. In the attic I use RG 8 for the antenna radiator, both center conductor and outside braid is used, I just tie them together.
The transmission doesn’t seem to be affected byte wood in the attic or things around it like boxes and that. However I have no way of seeing what effect it would have if those things were not there. It’s not rocket science to know the best antennas are high up and free from surrounding obstructions.
I see new discussions about the ATU. I have the original Talking House ATU. I tested it about two years ago; ok I was impressed, nice turnkey operation...However… I have made several simple inductance tuned loading coils that work just as good into a 10 foot vertical. But I do want to point out it’s a very nice turnkey operation with meter and all. I don’t know how long the plastic case would last in all kinds of weather, so I tested mine and then put it away and made my own loading coil for my other antennas.
If the ATU would be priced at about $60 (without 108” whip, ok I would say they get my money, otherwise there is noting magical about the ATU other than it’s a real convenience if you just want to put down a fence post and mount your antenna.
It seems I heard the price of their optional ATU is going to be in the $300 range.
To TheLegacy: At 1000 kHz quality RG-6 exhibits a loss of 0.2 dB @ 100 feet. Assuming a TPO of 35 mW, the 0.2 dB loss is equivalent to a 4.5% reduction of power. A 4.5% reduction of 35 mW results in 33.4 mW being delivered to the antenna/antenna coupler.
This reduction in power could only be measured with extremely accurate equipment and as such, one could not discern the difference between 35 mW and 33.4 mW on the receiving end.
Hi Peet, I am told by Bill Baker sooner than later. Most likely the end of January or early February.
ISS has announced that they will have the new iAM antenna and tuner (now called Range Extender 2.5) on display at their booth at the Dayton Hamvention in Xenia, OH this coming weekend.
The Dayton Hamfest is long over with.
Maybe he is talking about another smaller one somewhere else in Ohio? I knew Grand Ledge, Mi (West Of Lansing) had theirs either just before or just after Dayton.
My posting about the Dayton Hamvention was made several weeks ago (before the show) unfortunately it sat in limbo until a couple of days ago when it finally posted to the forum.