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Bird Termaline Model 61 (1 & 5W)
Posted: Thu Sep 28, 2017 10:01 am
by fineshot1
Looking for anyone with experience with this old workhorse.
I need to calibrate this great old watt meter. Both scales low
and high are off by about 25%. Some info but not a lot on the
internet and the guy at Bird says it is too old and obsolete
but i still have a good use for it.
Re: Bird Termaline Model 61 (1 & 5W)
Posted: Thu Sep 28, 2017 12:24 pm
by Audiotron
Hi ,
The times I came across this model measuring incorrectly was with R102 changed..
Re: Bird Termaline Model 61 (1 & 5W)
Posted: Fri Sep 29, 2017 4:43 am
by fineshot1
Audiotron wrote:Hi ,
The times I came across this model measuring incorrectly was with R102 changed..
Yes - I measured R102L at about 11.7K and R102H at about 12.7K. Both should be exactly 9.1K
and I have not taken apart the head and not sure about how to do that safely. I am in foggy
territory as to taking this head apart.
Re: Bird Termaline Model 61 (1 & 5W)
Posted: Wed Oct 18, 2017 7:50 am
by fineshot1
Today i swapped CR101 and CR102 and had positive results but still not
as accurate as i would expect it to be if it were properly re-calibrated.
Using CR102 in the Hi/Low selection ports gets the accuracy much closer
than before when using CR101. While using the low scale I measured an
HT output on 460Mhz 470 mW and using A General Dynamics R2670A measured
at 510mW. The GD 2670 and Bird 4304 match each other so I am confident that
I am close but no cigar.