Here is some data that may shed light on the discussion dealing with 962 PS
heatsink tempeature. These tests were performed on an OMNI-VI Option 3 and
961 power supply today.
73, Dave, K1FK
Fort Kent, ME
~~~~~~~~~~~
NOTE: The VI Option 3 has the Ovenaire MC43-1G crystal oven master
oscillator which is NOT powered up during times that the 961 PS is ON and
the VI is OFF (Early production OMNI VI+ radios before the TCXO was
incorporated maintained power to the oven when the VI+ POWER switch was in
the OFF state).
Temperature and AC current data taken with B&K Precision Model 390 DVM with
Type K thermocouple probe attached to 961 heat sink at top of fin adjacent
to Q1. The VI was in the transmit mode for 10 minutes at 100 watts output
into a dummy load, at which time the temperature stabilized at the reading
indicated. Output power was monitored with a Bird 43 wattmeter, 250 watt
3-30 MHz slug and with 0% reflected power from a Bird #8141 dummy load.
Relative humidity for all meaasurements was 35%.
Test Parameter 961 Input (amps) 961 HS Temp
961 OFF (ambient) 0.00 16.0* C
961 ON/VI OFF 0.30 20.0* C
961 ON/VI Recv 0.62 27.0* C
961 ON/VI Xmit 3.35 61.5* C
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