Recent content by mechteacher

Thank you very much for the input. I will continue checking and making updates here to keep everyone informed. 79 --... ...-- Bob K9HOU

I may have found the problem. C13 Capacitor from the parasitic suppressor to the air coil. I read it as 220 pF, not the 1000 pF rated. Parts on order. Thank you for looking at this for me. I will update when part is installed.

Tube plates are powered. Checked voltage at L2, (J3 RLY shorted) found 9.3 vac in stby and 3.2 vac in opr (S3 closed, & RelayRL1 closed). Continuity checked good, manual actuation to relayRL1 between FR IN (J2) to C8&9. Thank you again for the help.

Dr. Frankenstein, Thank you very much for looking at my problem. Here is what I just verified. I rechecked D4-15 and R 8,9,10,11 all checked good. Checked AC from transformer at the diode board, 1260 VAC. That was with tubes installed and no RF, amp pwr on, STBY switch in OPR. What next...

Here is the AL-811 Schematic

Ameritron AL-811 amp. Connected RF in to RF OUT, placed to on and into XMT OPR, Then was trying to tune the amp, Grid and Plate both spiked. After finding the error of the connection that caused Grid current to spike momentarily, the amp failed to operate. This amp has TOF-2 installed. TPS3 and...

This is the open frame relay. I have powered the relay and check continuity from the input coax connector. With the relay powered, transmit, there is open between the coax input and output. Relay not powered, the input and output have continuity. Not O-scope here..

Plate voltage and current are normal and current shows a minor decrease when going to transmit. Grid current does not move.

This is an early version. It has open frame relay with good continuity through each of the 3 pair. High voltage is there. Yes it keys to transmit with NO signal trough at all.

New request for help. My AL-811 was set with 572B was fine. Re-arranged the shack and may have transmitted into open coax.. Now Zero output Checked antenna (now) from amp input amp off. swr 1.02 at 51.2 ohms. Transmit 50 watts / swr 1.05 amp stby. AMP placed into transmit SWR at radio go...