Bob and Jack
Seems that if you are using that circuit and an ADC input in place of an analog? meter, you could use software to convert the ADC readings into VU meter,? S-meter, or anything else.? Might be a way to show Peak readings versus? Average, and even to calculate receiver input in Microvolts.
Arv _._
On Wed, Oct 28, 2020 at 11:26 AM Bob Lunsford via <nocrud222= [email protected]> wrote:
The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.
Bob ¡ª KK5R
On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via <jjpurdum= [email protected]> wrote:
Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??
Jack, W8TEE
On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via <nocrud222= [email protected]> wrote:
This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.
Bob ¡ª KKR
On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris < lorisbollina@...> wrote:
On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR
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Jack, W8TEE
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