Deano said:
With today's developments I am full steam ahead with trying to maximize things. It is so wonderful to sit in my comfy chair tonight and listen to a loud, clean hum-free AM signal.
In the time-honored spirit of experimentation, I am happy to provide the following information.
The Talking House remote ATU circuit diagram is shown as Figure 7 in the US patent #6973294 (Google the patent number). It consists of an RF transformer feeding two switch-selectable adjustable tuning coils and a circuit to sample the RF antenna voltage to drive the meter. The two tuning coils are provided to cover the broadcast band in two ranges, high and low frequencies.
The electrical principle of this tuning configuration is identical to the AMT3000 tuning configuration for the external base-loaded antenna: the tuning coil resonates in series with the capacitance of the antenna at the operating frequency. Physically, the difference is the TH ATU is adjusted by continuous movement of a ferrite core while keeping the antenna length constant while the base-loaded coil antenna is tuned by selecting coil taps and adjusting the antenna length. So, the ATU will work with the AMT3000 as long as the transmitter setup is done as it would be for the base-loaded antenna.
The AMT3000 must be get slightly modified per the instructions at
http://www.sstran.com/pages/sstran_amt3000mods.html The modifications are minor, but without the modifications, performance with the ATU or the base-loaded antenna will not be good.
Minimization of the coax length is important for both the Talking House and the AMT3000-Talking House ATU configuration because the coax adds loss to transmitters that already suffer from FCC power restrictions.
The AMT3000 base-loaded antenna has been optimized for efficiency. This includes the low-loss 3.5” coil and direct-connect to the transmitter via a short wire (no coax). The TH ATU configuration will suffer from the losses incurred by the small ferrite core tuning inductors, and the coax interconnect.
I understand, and encourage experimentation and I realize the base-loaded antenna is in a completely different arena when considering bulk, fabrication complexity and tuning complexity. I would encourage experimentation with the Talking House ATU. The results should be compared between the two alternatives. I expect experimenters will find the base-loaded antenna to be superior to the TH ATU.