| Author |
Message |
    
Mdiver
Member
Username: Mdiver
Post Number: 61
Registered: 11-2003
| | Posted on Wednesday, March 24, 2004 - 5:37 pm: | 
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The other night I was talking on side band with my 2547 with a older man and his friend and and they both said I was off Freq. by 5 well I could here him just fine and the other guy said the same thing but when the other guy talked I had to adjust my califier by 2..Ok then I asked them for a radio check on my mobile Voyage Vr-9000 well same results does this sound right.
Steve. |
Tech808
Moderator
Username: Tech808
Post Number: 1927
Registered: 8-2002
| | Posted on Wednesday, March 24, 2004 - 5:54 pm: |
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Mdiver,
Yes this is very common as the more people you are talking with, will show more are off a little as No Two Radios or Frequency counter's will generally read the same .
You were talking with two gentlemen that had already tuned in to each other and probably one of them was off to start with.
With them saying BOTH of your radios were off the same is strange for two different radio's.
That is like the CEF NET's, If I tried to tune to everyone it would be a nitemare, so I start out and leave mine set and let other's tune to me.
Freq Counter's are a wonderful thing to get you in close but then the Clarifier comes into play.
Lon
Tech808 |
Dindin
Junior Member
Username: Dindin
Post Number: 25
Registered: 2-2004
| | Posted on Wednesday, March 24, 2004 - 8:02 pm: |
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OK,you guys have me wondering how much my radios have to be clairified to be understood?I have run 2 different radios on the net and on both I more or less leave the clairifier about the 12:30 to 1:00 position and recieve all that I can hear with the exception of one LOUD member who drifts a little till warmed up.Of course I understand not everyone hears tone and pitch the same and after 15 years of racing rc aircraft and working in noisy factories my hearing loss has been on the increase latly.also I now wonder how many members I dont hear because of my ears and not my radio? |
Mdiver
Member
Username: Mdiver
Post Number: 62
Registered: 11-2003
| | Posted on Wednesday, March 24, 2004 - 9:55 pm: |
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Yes there is a very loud member on my end and I can't clarify him ... hey Dindin you said rc aircraft (remote control like models ))if so done that myself) yep your right on hearing Im a heavey equipment operator and tones are a big problem...
But the LSB everyone ((almost)) out there need to clarfied on my end
Steve |
Crafter
Advanced Member
Username: Crafter
Post Number: 996
Registered: 12-2002
| | Posted on Thursday, March 25, 2004 - 12:42 am: |
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Sorta helps ya sleep at night though dont it! I know mine does. That ringing! Mine was to much machine gun fire. |
Kc0gxz
Advanced Member
Username: Kc0gxz
Post Number: 664
Registered: 3-2003
| | Posted on Thursday, March 25, 2004 - 2:03 pm: |
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If you were to buy 2 or 3 identical brand new sideband radios, chances are VERY slim that they would be transmitting on the exact same frequency since there are many varibles to take into consideration.
For example, what was the room temperature when the upper, lower and A-M cans were set at the factory? What was the temperature of the frequency counter when it was calibrated?
Frequencies that you get when the cover is off the radio are all together different than what you will get when the cover is on. To get the corect frequency shift from A-M to USB and A-M to LSB can be vert tricky at times. Temperature has a great deal to do with the correct calibration of radios.
The best thing you could do for sideband radios is to UNLOCK the clarifiers. On SSB radios with both a Course-Tune and a Fine-Tune, usually the Course-Tune comes unlocked (varible) and the Fine-Tune is "fixed" or locked on transmit. This is perhaps the dumbest thing a SSB radio manufacturer can do to a SSB radio.
Those who buy a SSB radio and only use it in the A-M mode will never notice this problem. The dedicated SSB users will see this problem right away. By having both the Fine-Tune and Course-Tune clarifiers unlocked, the problem goes away because your transmit and receive frequency will then track together with both clarifiers.
You may wonder why SSB radios are locked on frequency. Back when sideband was first introduced, the clarifiers would move both transmit and receive together. This was legal because the tolerance of the transmitters was +/-.005%. This means the radio had a frequency range of +/- 1.3KHz from center frequency.
Many people modified their clarifiers so they could "slide" down 10 or 12KHz. This pretty much upset the FCC. And when they approved additional channels, (24-40) new regulations were imposed including the one that mandates all transmitters must be locked on frequency. This made anything more than a two person conversation difficult. Radios were off frequency and any third party listening would go nuts turning the clarifier back and forth.
Dedicated sidebanders have always wondered why the factories let radios go out the door that are off frequency. By law, they're not suppose to. The new tolerance is +/- .002%, giving them a leeway of just over +/- 500Hz and still be considered on frequency. In production the radios are set before having time to reach full operating temperature. This is the main reason why brand new SSB radios are off frequency out of the box.
All sideband clarifiers can be unlocked and expanded to a degree. Radios, like the Cobra 148GTL and 200OGTL for example are capable of sliding +5KHz and -12KHz without changing parts or adding chokes. Although it's nice to have capabilities to "slide" down 10 or 12KHz, a problem arises "WITH ALL CB CLARIFIERS".
The more range a clarifier covers, the more touchy it is to use. Not only that, but the farther down you go (after 5KHz) into the slide, the transmit and receive frequency will begin to split. It's just enough for a truely dedicated
sidebander with a good tuning ear to notice. The occasional sidebander will not.
Jeff, kc0gxz. |
