Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
Search
2 meter sideband audio
|
Today we set up a portable station with a 2 meter Diamond horizontal Yagi, and we made one contact with another station on 144.200. While both of us were on 144.200 USB, the other station's audio sounded slow and low pitched. We tried adjusting the frequency to see if we could get it centered and sound right like on HF, but there was no frequency that sound right... only low pitched or high pitched.
?
Is there an issue with IC-7000 2 meter SSB mode or is there something else I should try to adjust to fix the audio.
?
Thanks
73
John Denison
KD5YOU |
|
You need to put the RF tuning step at, or below, 100 Hz.? That will give you finer control of the "too-high / too-low" sound. I'm not sure how frequency-stable the IC-7000 is, but you shouldn't have any trouble in the 2m band.? On Sat, Jan 11, 2025 at 4:18?PM John Denison via <kd5you=[email protected]> wrote:
|
|
Several things...
?
For SSB 10hz is fine enough but at 100HZ not at all good.
I've used manpacks and older radios and 100hz does not cut it
unless both radios (both yours and the otherguys) reference
osc are spot on.? Usual case is they will not be.
?
The IC7000 will do 10hz tuning very nicely.? Its my primary
432mhz SSB radio and backup for all other bands.? I also
have for? 2m use a TT M526 (6M and 2M) and IC 251A
(2m only).?
?
?NOTE:? 2M SSB IS NOT CHANNELIZED.? The display on
most radios may say 144.2000 but I'll bet money they
are?actually not on frequency.? ?The fix is tune the
other guy in.? That's what the big knob is for.
?
Add the the above list a FT817 (with tcxo) and I reset
them or check them at least once a year and usually
I need to touch them to make sure they are within
20hz at 144mhz.
?
?
The indicated DIAL FREQUENCY IS NEVER the output
(or input) frequency unless the radio has a recently
calibrated TCXO.? Usual radio to radio variation? on
the band is 100HZ wither way (low or high) or more
by experience.
?
IC7000 dial? accuracy is only ok but its stability is good.
There is a menu option for correction but you need a
reference source (wwV at 10 or 20mhz) to set it correctly.
By correctly I mean to less than .1hz error.
?
?
--
Allison |
|
Most modern radios frequency error increases (multiplies) with
operating frequency.? So a 10Hz error at 14mhz is likely to be
not noticed at 50mhz its about 25hz at at 144? near 100hz.
?
The dial is the "programmed frequency" to the internal logic and
microprocessor and with errors the actual output frequency will
be off.? The output frequency contains error based on the
system clock (timebase).?
?
?
--
Allison |
to navigate to use esc to dismiss