receiver input impedance is usually not too important... but proper matching
can increase the signal getting to the receiver and give better sensitivity.
use the same type of matching network as for a transmit antenna, though
smaller components are permissable of course. adjust for max receive signal
unless you have proper test equipment to measure input impedance. some old
radios included a simple peaking control that did some input matching, check
the schematic for anything adjustable before the first rx rf amp tube.

"Edgar" wrote in message
...
Hello,
I've purchased an 1962 tube HF receiver. Well the problem is I don't know
exact antenna input impendence value of it. I use simple 40m. dipole on a
regular TV cable of 75 ohm. I would like to do some experiments with
random
wire, and 50 Ohm coax or 300 Ohm ladder line for dipole. Is there any
circuit that can help me to mach the impendence?

Thx,
Edgar
73!