[Milsurplus] BC-348R Oscillator Issue output Frequency is 0 for part of band 4 : 6 - 9.5 MC

jphutch60bj jphutch60bj at gmail.com
Thu Aug 21 19:24:01 EDT 2025


Reading the Manual TO-12R2-3BC-112, Revised 15 April 1957,  Page 4-3 
paragraph 'e'.

On the four lower frequency tuning bands the
oscillator frequency is higher than the desired signal
by the intermediate frequency. On the two higher
frequency ranges, bands 5 and 6, the oscillator is on
the low frequency side of the desired signal. The latter
results in a more uniform tuning ratio over these
bands and increases the image rejection ratio.

Before I start doing Brain surgery on BC-348R by pulling the RF Units .....

I was Checking Oscillator output frequency with a frequency counter, 
tweaking the outputs from the oscillator on each band.

Band 4, frequency range of : 6 - 9.5 MC,  reading the manual the 
Oscillator High Side output should be between 6.915 - 10.415 MC for band 4?

My Oscillator *goes dead no output*,  between DIAL Frequency reading 
of:  7.2  to 8.8 MC - which equates to an Oscillator output frequency 
of  "+.915"  should be between  8.115 - 9.715 MC.

*Issue the output Frequency goes to 0 as measured  on Pin 8, VT-91, 6J7.*

*If the manual is not wrong,  why is the oscillator output dropping to 
0, on this one band?*

*It aint the tuning cap!-} *, as there are no problems with other bands.

Thanks for you thoughts in advance.

JPHutch


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20250821/7be4fb21/attachment.html>


More information about the Milsurplus mailing list