Bicycle antenna for long wave 200 khz

[biff44]

the only antenna i am aware of at that frequency that will fit on a bicycle would be a ferrite rod, with copper wire wound on it.

You could try a whip, but it would be sooooo much shorter than a quarter wavelength, the antenna impedance will be very high ( perhaps 5,000 ohms) and would not be efficient. But with a high impedance amp right at the antenna, a whip might work with a strong signal.

 

[dr pepper]

I dissed the loopstick as directionality would be an issue on a bicycle.
However the fet buffered 35 x 80 mm plate at with a fet buffer right at the base works well.
I dont spose a 500 meter 1/4 wave whip would be all that practical on a bicycle.

 

[biff44]

looks like people DO make active antennas in this frequency range. I assume they are all active to solve the problem of the very high radiation resistance of the electrically short antenna. I see whip antennas and discone antennas out there.

here is one example, that uses a 1 meter tall whip

https://www.prc68.com/I/LF-Ant.shtml

 

[dr pepper]

You mean people make the ant commercially, of course they even make the PA0RDT miniwhip commercially.
Mines been going for a month on my bicycle now, the only finnicky thing with it is that its sensitive to noise from the dynamo.
Isnt radiation resistance low, I thought radiation resistance shunts the antenna.

 

[dr pepper]

If anyones interested I've been working on a circuit to receive radio 4 on 198 khz, here it is:
The 70mm disc ant goes to a yellow 455 khz IF transformer padded down to 198, then via a fet to a black IF trans, then through a voltage controlled attenuator on to a cascade tranny amp, via an op amp to both a rectifier for the agc, and to the audio amp, its a cobble together of other circuits I've made.
It works quite well on the bench, even though its on breadboard.