Frequency fluctuates on transmit

[Coyoteman]

I hooked up the frequency counter on one of my radios, on a.m. when I key up it's rocksolid but when I switched to lower sideband or upper sideband I notice the frequency jumping around its up-and-down up-and-down and it settle on the right frequency then back to fluctuates. Any ideas on what causes this

 

[CbRadiosPRONTO]

Which radio?
Which freq counter?

If it's an inline freq counter (using the coax), it has to be able to read SSB. Also, you'll probably have to put a 1khz tone through it for it to read. If it's a counter that plugs into the freq counter plug I'm the back, then you might have a problem with the radio.


CbRadiosPRONTO

 

[Coyoteman]

It's a RadioShack 465 it's an external frequency counter you plug in line. You plug-in. from the radio to the frequency counter from the frequency counter out to the antenna. And it only fluctuates on single sideband on am it's rocksolid. Maybe it needs to warm up a little bit or something I'll try that later tonight and later I will post what brand of frequency counter it is.

 

[CbRadiosPRONTO]

It probably doesn't read ssb but if it does, there has to be a steady signal generated into the mic. You can google a 1khz time and play it back through a speaker if its loud enough. Hold the mic against the speaker. Still, it may have to have the capability to read ssb. Idk. ie: some Dosy's read ssb and am and some just read am. You still have to inject a time, though. There is no rf output (carrier) on ssb unless it's modulating.


CbRadiosPRONTO

 

[camaro1]

yup,, normal for side band,, download a 1khz audio tone and play it through a speaker or headphones and then hold it to the mic while the tone is playing then take a reading,, the freq counter will show your transmit freq but it will be offset 1000 hz on the display higher or lower than your actuall frequency depending if your on lsb or usb

 

[Coyoteman]

I will do that thanks

 

[CbRadiosPRONTO]

Ah. Yes. Thanks for the clarification on the offset. I'm used to the Dosy having a USB and LSB switch.


CbRadiosPRONTO

 

[Captain Kilowatt]

Indeed as stated there is no carrier on SSB and since the power fluctuates down to zero the counter cannot lock onto a signal because it is not there half the time.

 

[tba02]

There are also apps for that 1 khz tone
https://play.google.com/store/apps/details?id=com.jm.android.frequencygenerator

I just hold the mic right up to the phone.

 

[binrat]

There are also apps for that 1 khz tone
https://play.google.com/store/apps/details?id=com.jm.android.frequencygenerator

I just hold the mic right up to the phone.

Now that is handy.

 

[Road Squawker]

Now that is handy.

this is the one that I use http://r.search.yahoo.com/_ylt=A0LE...gssdxIZI8FKBopT2kg-?p=tone+generator+software

it can generate some REALLY irritating roger beeps ^^ ab v c^^^^ ab v c^^^^ ab v c^^^^ ab v c^^

 

[w9cll]

What we need on this site is a sticky on how ssb works, I feel that a lot of people really don't understand it. No offence intended towards the op.

 

[357magnum]

I agree with W9 , after 45 years with a CB radio I didn't understand it til I join this forum an have been able to pick up info from other posts .op:

 

[vo1ks]

Back when I was messing with modding CBs, a few came through that would warble on transmit. The voltage feeding the clarifier was not steady. Varying output power would cause the voltage to swing, and then the varactor diode would change value, causing frequency shift.
If you have a modded radio that has the clarifier functioning in transmit mode as well, ensure the voltage supplied remains steady. Instead of powering from the main 12V line, move it to a +8V regulated line and install a suitable capacitor.

 

[Captain Kilowatt]

Back when I was messing with modding CBs, a few came through that would warble on transmit. The voltage feeding the clarifier was not steady. Varying output power would cause the voltage to swing, and then the varactor diode would change value, causing frequency shift.
If you have a modded radio that has the clarifier functioning in transmit mode as well, ensure the voltage supplied remains steady. Instead of powering from the main 12V line, move it to a +8V regulated line and install a suitable capacitor.

I remember hearing this when some guys would park their SSB mobile rig and talk until the battery started to run down. When they got reports of FM'ing they knew it was time to start the vehicle and recharge the battery..........if they could.