Fischer - Spider Coil Parameters

[Andrew]

Hello!

I'm looking for parameters of Fischer Spider coil (for 1235,1266),
because I want to build similar open center coil.
I must know electrical parameters especially resistance of TX, RX coils
Please send me info if you know this parameters - my e-mail adress is
[email protected]

[Reg]

Re: Fischer - Spider Coil Parameters

Hi Andrew,

Fisher used to sell the schematics for their detectors and they did display the general coil parameters on the schematic. I am assuming they still do and what information is shown on the schematic is correct.

It appears from the schematic I have of the 1235, the xmit coil is 2.4 mh and the receive coil is 10.8 mh. Also, there is no indication of any capacitors mounted in the coil housing.

I cannot tell you the resistance nor the number of turns of either winding, but hopefully this information will help some. Unfortunately, I do not have a coil to measure to verify the above numbers or to provide any other information.

[walkman]

I'm looking for pcb 1235 Fisher's scheme. Also what are the values of the coil

[kt315]

...

Originally Posted by w5cdt
Well if the Fisher 1225X RX coil is off-frequency it is not by much.
Check the resonance frequency of the RX and TX coil/cap pairs
I measured in the 1225x coil below:
RX - 12.5 millihenry and 0.068uF = 5.46 kHz
TX - 2.5 millihenry and 0.33uF = 5.54 kHz
My inductance measurements may be slightly off but as you can
see the RX and TX resonances are very close.