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OFF FREQUENCY ON SSB ALSO OFF ON AM?

VKrules pretty much answered this for you on post #7.

SSB is typically 3 Khz bandwidth with no carrier so even just a few Hz off can be noticed if you have good ears.

AM mode with a bandwidth of 6 KHz and FM at 12 Khz or more and both being carrier modes, it's not likely anyone will notice even a couple hundred Hz off especially with CB radios.

Every CB or glorified 10 meter radio I ever owned has been off some on SSB, Some more than others. At least the RCI 2900 series and the President HR series didn't seem to drift after they warmed up.
 
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As long as the tx/rx on the Madison are the same, I wouldn't worry about it too much. Since your clarifier is unlocked, you can compensate (as your pic shows). If it bothers you to see the display is off, you should be able to adjust things fairly easily.

73,
Brett
 
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2RT307 said:
As long as the tx/rx on the Madison are the same, I wouldn't worry about it too much. Since your clarifier is unlocked, you can compensate (as your pic shows). If it bothers you to see the display is off, you should be able to adjust things fairly easily.

73,
Brett
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I actually never considered that. Maybe it's the frequency counter that's off a.couple of Hertz and not the madison itself. It doesn't bother me at all. I just figured since I use the radio on am occasionally I'd like to set the clarifier so that it transmits on the frequency/channel that I'm on. From the replies I am going to assume that since it's difficult to tell if the received stations are exactly on frequency it's probably just as difficult for them to tell if I'm transmitting exactly on frequency if the AM is off by a couple of htz. That's on am of course. Thanks. 73
 
vkrules said:
Not sure what you are saying.
So you are 200hzs off?
Frequency counters will show actual frequency as apposed to carrier frequency. i.e lsb will be 1.5 low usb will be 1.5 high .with am in the middle (carrier frequency) ( the difference between a counter as apposed to a display. most are displays not counters)
Modern cbs show carrier freq on their displays.
HF sets can be adjusted for the offset to show either carrier or actual frequencies
if you go back about 15 years hf sets would show actual freq and would be out 1.5 if you used them on CB The norm these days is to show carrier freq .

And to answer your question no Am wont necessarily be out if ssb is.

Also am and especially Fm are much wider modes and 100 to 200 hzs wont make a rats arse bit of difference to you.
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Thanks vkrules.
 
ex.GIF
 
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Sonar said:
Two (2) Hertz. Here endeth the lesson. Thank you. 73
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School is back in session. The correct answer is 200 Hertz NOT 2 Hertz. Everything to the RIGHT of the last decimal point is fractions of a kilohertz, or 1000 hertz thus 0.2 of 1000 hertz is 200 hertz. Just trying to steer you in the proper direction of understanding.
 
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Captain Kilowatt said:
School is back in session. The correct answer is 200 Hertz NOT 2 Hertz. Everything to the RIGHT of the last decimal point is fractions of a kilohertz, or 1000 hertz thus 0.2 of 1000 hertz is 200 hertz. Just trying to steer you in the proper direction of understanding.
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That was for Sonar to answer post #21.

Good explanation on your part though. I brought this up because I have heard many times on the CB and occasionally on the HF bands people get this wrong on the 6th digit.
 
I could use a little clarification on the difference between SSB and AM as far as frequency shift is concerned.

As I understand it the reason you have a clarifier for SSB but not on most AM only radios is because on SSB the "carrier" is provided by the receiver, as such the carrier frequency and the received signal are from two different sources and need to be matched together to properly demodulate the signal. With AM though the carrier comes in with the signal so both the carrier frequency and the sidebands are from the same source, as such as long as the signal is within the passband of the filters the receiver can demodulate it. If this is true it would seem to me as though small shifts/drifts in frequency shouldn't really effect AM at all.

Am I off base in thinking that the OP has nothing to worry about on AM or do I need to go back to school myself?

PS: a couple of the posts above mine seemed to indirectly touch on this so I thought this question would be relevant to the topic and probably helpful to the OP.
 
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StrangeBrew said:
I could use a little clarification on the difference between SSB and AM as far as frequency shift is concerned.

As I understand it the reason you have a clarifier for SSB but not on most AM only radios is because on SSB the "carrier" is provided by the receiver, as such the carrier frequency and the received signal are from two different sources and need to be matched together to properly demodulate the signal. With AM though the carrier comes in with the signal so both the carrier frequency and the sidebands are from the same source, as such as long as the signal is within the passband of the filters the receiver can demodulate it. If this is true it would seem to me as though small shifts/drifts in frequency shouldn't really effect AM at all.

Am I off base in thinking that the OP has nothing to worry about on AM or do I need to go back to school myself?

PS: a couple of the posts above mine seemed to indirectly touch on this so I thought this question would be relevant to the topic and probably helpful to the OP.
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Being 200 Hz off on AM is pretty much within manufacturers tolerances and is nothing to be concerned about whatsoever. Being 2 KHz off however will begin to have the effect of making you sound a little "fuzzy" in some cases.
 
Sonar said:
View attachment 18175 My uniden Madison seems to be off frequency.
On SSB it's easy to tell . I will clarify onto the locals whom for a large majority are operating new hf's.
If I'm correct those transceivers are on frequency.
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If you are talking about HF amateur radio sets then no they're not unless they're fitted with a TXCO which many of those used on 11m are not. My Kenwood TS480SAT, brand new, was roughly off by the same as you claim your radio is, so was my TS590S. The only amateur radios I've had which have been "accurate" are those which have had TXCOs fitted either as standard or I've added. My TS480SAT now has a TXCO fitted and its still 8Hz off.

It costs a lot of money and the use of something like a Rubidium Frequency Reference Standard or GPS disciplined oscillator to get the kind of accuracy you are expecting on here. On CB/11m and even amateur radio unless you're doing stuff like using below the noise floor modes like JT65 where frequency and timing accuracy is absolutely critical then it is simply not needed. Within 100-200Hz is more than sufficient especially for channelised modes on AM and FM. On SSB you can't be sure that both ends in a contact are anywhere near accurate so even if you fix yours spot on you're going to find yourself in the same situation because the other station won't be.

Whatever you do though don't lock the clarifier to do both TX and RX because you end up in the daft situation if you both have where you're just chasing each other up and down 10kHz because you'll adjust yours to take into account his "off frequency" signal which also moves your transmit frequency so then he adjusts his clarifier to account for your sudden change in TX frequency which then alters his TX frequency so you re-adjust yours etc etc etc. Thats the reason that CB manufacturers only have the clarifier work on RX only.
 
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fourstringburn said:
Are you sure it isn't 200 Hz ???
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I'm so confused! I think my frequency counter is showing the sixth digit off by 200 hz. If I'm incorrect please explain. The chart someone posted is great but my a.d.d makes comprehending certain things difficult. Thanks. 73
 

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