HFH is a extremly sensitive radio system with a defined amplification to readout the field strenght on the large instrument. There is a attenuator switch.
Like the most Rohde + Schwarz test gears of the old time it is inside a silverplated highlight of old engineering, featuring a family of 14 tubes.
The restoration is to do in 3 parts.
Part 1: the instrument self.
The pre owner, may be a HAM, made a manipulation of the wiering to use it as a radio. The most of that I have repaired to get the original functions back, but not complete, still missing 2 of the special coaxial plugs to continue. The function of the socket for the loop antennas is back to life. There was a bad tube, a second was missing, both in the loop system preamplification. This is repaired. Actually the HFH is in a working condition to do measurement (or listening radio...) using it`s loop socket
To repair is: 60 ohms antenna input with overlay of DC 12V, IF out and some little things to do..
Part 2: missing the Loops.
HFH needs a set of 3 loops and a rotating feet socket plate to come in a working condition. I have to rebuild that complete.
Part 3: external Ground plane antenna missing.
The external ground plane antenna is to rebuild complete. It contains in the socket a germanium driven DC DC converter to feed a tube with stabilized 110V, and a tube as kathode follower to connect the antenna to the 60 ohms cable connection.
A lot of work, also a lot of fun.
greetings
Martin