[Elecraft] S-meter calibration

[Mike Harris]

G'day,

2)    Tapping the SUB button does indeed change the display from RF to SUB
and the SUB legend on the display flashes.  However, changing the SMTR
parameters in SUB mode does not seem to change the Sub-RX SMTR settings.
Instead it changes those of the main-RX.  Maybe I'm being particularly
thick and somehow not entering the correct configuration.

There isn't any reference to this method of setting the Sub-RX parameters.
Maybe the whole subject needs to be reviewed, tested and the procedure
re-documented if necessary.

Also, often but not every time, in normal operation activating B SET to
transfer the S-meter display to the Sub-RX doesn't until the main-RX RF
Gain control has be turned down maybe 20-30 degrees rotation from full
clockwise.

My Sub-RX consistently shows one S-unit less than the main-RX.  The audio
is also less, requiring maybe 20 degrees more AF gain to balance with the
main-RX.  I have displayed both audio channels in Spectrogram-16 using
stereo mode and there is a 3-4dB difference in the displayed noise and
signal between the channels.  I am trusting that my sound card is not the
cause of this and it is matching what my freshly cleaned out ears tell me.

Does the main and sub RX share the AGC settings?  If not and the Sub-RX
has defaults and the main-RX modified settings then this could have a
bearing on the output of the two RX's.

Maybe I am getting anal after all.

Regards,

Mike VP8NO

----- Original Message ----- 
From: "Joe Subich, W4TV" <lists at microham-usa.com>
To: "'Mike Harris'" <mike.harris at horizon.co.fk>;
<Elecraft at mailman.qth.net>
Sent: Wednesday, November 19, 2008 7:14 PM
Subject: RE: [Elecraft] S-meter calibration


|
| 1) calibrate the subreceiver S-meter using the BNC (AUX) antenna
|   instead of the main receiver so that the splitter losses
|   do not impact the calibration.
|
| 2) to calibrate the subreceiver enter CONFIG:SMTR SC or
|   CONFIG;SMTR OF and tap the SUB button to select sub RX.
|   RF will change to SUB in the VFO A display to indicate
|   that the subreceiver calibration is being adjusted.
|
| 73,
|
|   ... Joe, W4TV
|
|
|
| > -----Original Message-----
| > From: elecraft-bounces at mailman.qth.net
| > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Mike Harris
| > Sent: Wednesday, November 19, 2008 2:42 PM
| > To: Elecraft at mailman.qth.net
| > Subject: [Elecraft] S-meter calibration
| >
| >
| > G'day,
| >
| > I have been trying to perform the Sub-RX S-meter calibration
| > and find that
| > following the procedure in the owners manual (D1 p50) doesn't
| > work, at
| > least for me.  There is no way I can display the Sub-RX
| > S-meter reading
| > and enter the Config menu options required to calibrate the
| > Sub-RX.  The
| > display keeps reverting to the main RX.  Confirmed by the display
| > responding the main  RX RF gain control.
| >
| > The radio is loaded with 02.67/01.96/00.02 firmware.
| >
| > 1.    Main RX calibrates OK. (XG1)
| >
| > 2.    Enabling SUB drops the S-meter reading on the main as expected
| > because of the passive splitter loss.  I would assume that
| > calibrating
| > with the Sub-RX sharing the main antenna path the CONFIG:
| > SMTR OF would
| > need to be adjusted to match the S-meter reading of the main
| > RX, not S-9.
| > Using the AUX input for the Sub-RX has its own calibration issues.
| >
| > Don't get the idea that I'm coming on all anal about the
| > S-meter, I would
| > just like the two RX path readings to match +/- not too much.
| >
| > Regards,
| >
| > Mike VP8NO