Re: My Hilltopper 40 is alive (sort of)
Gary Kohtala <gary.k7ek@...>
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Hmmm.. Thanks Chas. What I would really like to do is increase receiver audio amplitude and decrease sidetone amplitude.
It sounds like both are tied to R9. The sidetone is so loud that it hurts my ears and makes my tinnitus kick up.
I did some reheating of solder joints but no noticeable change. I did notice on some louder signals like the RTTY that's
all over 40m causes the receiver to go into a screeching mode that blows my ears out. I am not sure what that is but
powering off and back on makes it go away. Guess the RTTY is often so loud that it overloads the receiver. Anyway,
thanks for your suggestions. I still have to build my Hilltopper 20. Will be interesting to compare the receiver
performance in both. Have a great weekend.
On Friday, February 8, 2019, 08:55:55 PM EST, Charles W. Powell via Groups.Io <doctorcwp@...> wrote:
Gary, I don't know how to quantify this exactly. I found my Hilltopper radios have all had minimal background noise. If you want to increase the audio output of the rig, you can DECREASE the value of R9. I actually increased it because the rig to me is so boisterous, for the most part, that I wanted it a little quieter and to make the audio chip less prone to overload. I hear a fairly comfortable signal at -107 dBm, which is generally about where the noise floor sits on any given band on any given fairly quiet day. R9 is 22K - try a 10K or what-have-you, or if you don't want to remove it, put another resistor in parallel on the bottom of the board. Another 22K on the bottom will give you about 11K all together. (I went up to 100K on mine, but I might end up modifying that after I use it in the field with that configuration.
I also use earbuds with this radio because they are more efficient than most headphones.