Why no UHF converters with RF amp?

[Steve McVoy]

The U70 has two IF amps, but no RF amp. The CT-100 doesn't have a UHF RF amp, and I don't know of any 50s tuner that had a UHF RF amp.

[dieseljeep]

Originally Posted by Steve McVoy

The U70 has two IF amps, but no RF amp. The CT-100 doesn't have a UHF RF amp, and I don't know of any 50s tuner that had a UHF RF amp.

Milwaukee was one of the larger cities that had UHF channels. Originally they were really low power. Anyone that wanted decent reception on UHF, had to install a corner reflector type UHF antenna.
It had to be a cost factor, for the manufacturers. IIRC, amplifier tubes made for UHF frequencies were rather pricey.

[jr_tech]

Originally Posted by dieseljeep

Milwaukee was one of the larger cities that had UHF channels. Originally they were really low power. Anyone that wanted decent reception on UHF, had to install a corner reflector type UHF antenna.

Here is the first commercial station, KPTV ch 27 in Portland Oregon... 1 kW transmitter, with enough antenna gain to bring the ERP to 17.6 kW. Rain, wet trees, wet lead-in wire and hills made for generally poor reception... boosters/rf amplifiers, had they been available in 1952, would have sold like hotcakes.
http://www.ggninfo.com/May05.htm
jr

[Geist]

Hi All;
I have a book from the early 50's, that has building instructions for both an RF Amp and a UHF converter.. It I think.. "78 Electronic Radio and TV projects".. It has a bunch of stuff.. By (I THINK) Popular Science..
THANK You Marty

[cbenham]

Originally Posted by Steve McVoy

The U70 has two IF amps, but no RF amp. The CT-100 doesn't have a UHF RF amp, and I don't know of any 50s tuner that had a UHF RF amp.

I'll *guess* [until Old TV Nut laughs at what I'm about to write] that the crystal mixer doesn't work very linearly with high level UHF signals. Amplifying the incoming UHF might overload the crystal and cause it to make some weird
unintended harmonics that would show up as beat notes or moire on the
TV screen. Again, just a guess. [Running for the deepest corner of the basement...]

Cliff