FCC Allocates 630 & 2200 Meters, Upgrades Amateur Status on 160 Meters

[kb2vxa]

OOOoooh that's cold!

Lowfers have to run several hundred watts to get 1WEIRP out of the antenna, Crown amplifiers have an excellent high end but they're awfully expensive. You don't need a vertical tall as the WTC, an umbrella antenna is about 200ft high and has fairly good efficiency. Still I wonder, that's a band where the lights are on but nobody home. Too bad when a club bought the old WSC marine shore station in West Creek, NJ and set up the W2WSC club station they grounded the 300ft tower and put antennas on it, if left alone it's perfect for the 472-479KHz band.

Funny how the FCC dragged its feet for so long and gave Amateur primary allocation on 160M, the last LORAN C radio-navigation transmitter went dark so many years ago.

[X-Rated]

OOOoooh that's cold!

Lowfers have to run several hundred watts to get 1WEIRP out of the antenna, Crown amplifiers have an excellent high end but they're awfully expensive. You don't need a vertical tall as the WTC, an umbrella antenna is about 200ft high and has fairly good efficiency. Still I wonder, that's a band where the lights are on but nobody home. Too bad when a club bought the old WSC marine shore station in West Creek, NJ and set up the W2WSC club station they grounded the 300ft tower and put antennas on it, if left alone it's perfect for the 472-479KHz band.

Funny how the FCC dragged its feet for so long and gave Amateur primary allocation on 160M, the last LORAN C radio-navigation transmitter went dark so many years ago.

LORAN A went dark in the 70's. LORAN C went dark in this millennium.

[HUGH]

There are a few audio amplifiers which will be satisfactory on 136kHz, examine the output and driver transistors and it should provide a clue. I've run one for a while up to 300W input using a 300W audio amplifier kit from China. Being linear it will dissipate some heat but I've fitted cooling fans and it runs cool. The power transistors have an ft of 15MHz but I've now fitted some with an ft of 30MHz.
I found it would actually take well over 400W from a +/- 30V supply and seemed happy without over-heating but as soon as I left it for an hour, half the power transistors popped. "Mea culpa".

This weekend I'm going to see if Vbe was exceeded, perhaps that induced the failure.

The amplifier output goes into a large, multi-tapped iron dust toroidal transformer using a "yellow/white" type, these are good for LF and I think the "green/blue" are OK too. The antenna is largely vertical (not very high however) with horizontal wires for top loading and a useful ground system consisting mostly of fencing wire and anything else metal in the vicinity. There is a multi-tapped toroidal loading coil on an unknown ferrite which tunes it all up nicely.