Re: Completed my QCX #ubitx

pat griffin

Thanks so much. Just the data I need. 
Pat aa4pg

On Jul 6, 2018, at 10:44 PM, Ralph Mowery <rmowery42@...> wrote:

Pat here is some of what I measured when using a service monitor.

Voltage DC across C4.

4 volts was the maximum with -40 dbm input to the antenna connector.
3.9 V -50 dbm
1.8 V -60 dbm
.55 at -70
.1 V at -80 dbm
.03 at - 90 dbm

.4 V at -73 dbm which is 50 uV , the socalled s-9 signal .

Using the 2 line by 16 charicter display I adjusted the display so tht 50 uV shows up as 3 bars.
6 bars is -63 dbm. One + is -57 dbm and two ++ is -51 dbm.
That seems to make the meter show up for me using an off center fed dipole on 80 and 40 meters.

73 de ku4pt

On Fri, Jul 6, 2018 at 8:10 PM, pat griffin <patgriffin@...> wrote:


Can you tell what voltage levels you are seeing there? On a strong signal I see about .4VDC across C4 of the AGC circuit.



From: <> on behalf of Ralph Mowery <rmowery42@...>
Sent: Thursday, July 5, 2018 9:20:55 PM
Subject: Re: [BITX20] Completed my QCX #ubitx
If you install the AGC kit you can just use it for the S-meter.  Just tap off the first pin where the several jumper pins are for the delay. Works fine.

On Thu, Jul 5, 2018 at 9:48 PM, WD8WV <juddie.d.burgess@...> wrote:

I haven't built the S-Meter circuit yet.  I had it turned on but it really isn't doing anything, don't know why sometimes I see what appears to be signal since there is no circuit in it yet.  I have to order the LM358 chip, everything else I have.  I was going to do the circuit with the LM386, which I have 3 of those from where I was building Pixie kits.  I bought several and have 3 new ones left.  Dr Lee, KD8CEC texted me on his blog that it would be better to use the LM358 chip.  I just received in the mail the TX/RX pop fix kit and the AGC kit that I read about.  Of course I have never done SM soldering, so don't know if I will be able to do this.
Judd, WD8WV

Join to automatically receive all group messages.