Re: Hilltopper mod performance

Dave Benson
 



Thanks, Chas!

If you've already got enough audio, you're done- the replacement IC is the 'biggie'

73- Dave


On Fri, Apr 12, 2019 at 7:49 AM Charles W. Powell via Groups.Io <doctorcwp=yahoo.com@groups.io> wrote:
I replaced the audio chip in one of my Hilltoppers last night and hooked it to the signal generator.  -73 dBm - great! -107 dBm, still great.  Then for the more difficult tests.  -33 dBm used to send the radio into its howling squeal.  I turned down the gain at -33 dBm and slowly turned up the RF gain.  So far, so good; no squeal.  So rinse and repeat at 0 dBm.  With the gain at full I couldn't leave the ear buds in place, but no squeal.  Next test: full RF gain with a sudden signal at 0 dBm.  NO SQUEAL.  Now I have to admit that I need to change out the RC combination, but I still don't expect any significant changes in performance.

Just for reference, I don't think input to any of my radios approaches 0 dBm even when my neighbor, 1 mile away, is transmitting at 1.5 kW into his phased arrays pointed right at me.  It's not an RF level you are likely to encounter in the real world.

Dave has come through for us again, making a great little radio even better.

72,

Chas - NK8O

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