Utah Radio UAT-1 Transmitter

Initial Testing and Problems

• Only way to tell what power output is, is to read off of the current ammeter on the antenna unit
• The meter is calibrated from 0-5 rf amps which is fine for the 500 watt rf deck but way to large for the output of 80 watts
• I found the best way to tune the final was to use an old rf field strength meter
• When the final was tuned properly, for some unknown reason there was arcing going on inside the meter face of the oscillator ammeter. I've never seen that before but the meter case being metal very likely contributed to it happening. After this happening in the first days of the transmitter working properly, it seemed to cease.
• The UAT-1 was designed to have the oscillator running all of the time. In the "old days" that didn't present a big problem because most likely your contact was also "rock bound" and wasn't on your frequency anyway. Today, its very annoying . . . at least to me.
• The solution was to key the oscillator the same time the amplifier was keyed. In theory, it was a great idea. In reality it caused the dreaded CHIRP.
• A look at the schematic showed the problem. The voltage for the oscillator was taken off of a voltage divider resistor which also provided the B+ for the amplifier stage. Problem: Voltage dividers have terrible regulation. The voltage for the oscillator just couldn't come up fast enough when the transmitter was keyed to prevent a very small change in frequency - CHIRP ensues when this condition occurs.
• The solution was to install a separate power supply for the oscillator itself.
• PROBLEM SOLVED