First attempt to drive amp with more than a CB. Amp was running NOS 300A tubes. One is gold color the other more common silver color. Watt meter is a 1990's Radio Shack.
When driven with 5w AM from the Yaesu, I see 500w PO. Any more than 5w drive, amp bogs down, running lights dim (lights powered by a separate transformer). Plate current at 500w is 300mA which I thought low for 2 tubes. Plate voltage on standby is 2.4k which decreases to 2k on transmit. These tubes could heat a small room. Data sheet states 250mA max plate current.
SSB PO peaks about 600w with same 5w drive. Not much difference from AM, I expected more swing on SSB. No Control Grid current that I can see. 20mA Screen current.
I’m disappointed at the max drive issue but 5w In to 500w Out is a 1:100 increase. The dimming panel lights suggest amp starved for current. Using 15A fuse on mains for Plate & Screen transformers.
n2eye
When driven with 5w AM from the Yaesu, I see 500w PO. Any more than 5w drive, amp bogs down, running lights dim (lights powered by a separate transformer). Plate current at 500w is 300mA which I thought low for 2 tubes. Plate voltage on standby is 2.4k which decreases to 2k on transmit. These tubes could heat a small room. Data sheet states 250mA max plate current.
SSB PO peaks about 600w with same 5w drive. Not much difference from AM, I expected more swing on SSB. No Control Grid current that I can see. 20mA Screen current.
I’m disappointed at the max drive issue but 5w In to 500w Out is a 1:100 increase. The dimming panel lights suggest amp starved for current. Using 15A fuse on mains for Plate & Screen transformers.
n2eye
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