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frq. tolerance ??

B

BOOTY MONSTER

Guest
my uniden 78ltw from sparkys arrived today . ill install it tomorrow . the invoice says the radio does "3.1 watts unmodulated" and "32.4 watts modulated . which is fine for running a lil amp . they measured frq. tolerance at ".0001" . what is frq.tolerance and is .0001 a good measurment ? im sure ham radios are 10 to 100 times better but is .0001 very good for a cb or even a export radio ? im thinking frq. tolerance has something to do with how narrow/wide or on center the tx/rx frequency is for the channel chosen . the spec sheet for the uniden says a frq.tolerance of .002 so i guess im doing good .


uniden-pc78ltw-lg.jpg
 

Beetle is correct,that "0.0001" needs to have a value. usually it is expressed as ppm or parts per million but sometimes it is expressed a s a percentage. I can't see this case as ppm however. Man that thing would bea the Cesium standard for freq tolerance. LOL. Even if that figure is percentage that is very good tolerance. BTW tolerance does mean how much the freq may vary from what it is supposed too.
 
I'm wondering how that radio can achieve 32 watts of rf power output. It is a single final radio, correct?
Asuming it's not just a wild claim, how would you get that from this radio? Is this radio a 1969 or a MOSFET? I have just never seen more than about 20-22 watts out of a standard CB radio, and if you were getting that kind of power, wouldn't it likely be stressing the final transistor?
Just curious, and looking to learn something.
 
Since your uniden CB is AM only, the frequency tolerance isn't so critical. I t seems you can be up to 1KHz off frequency on AM, and it is barely noticable. But on SSB, if your even 100Hz off then you will notice, but its not an issue for this radio.

here is your definition of frequency tolerance.
http://www.oscilent.com/spec_pages/PNDescrpt/Tol_over_Temp.htm

+/- 0.002% = +/- 20PPM
so 27.185 * +/-20 = +/- 550Hz max. error

It seems when they say "tolerance", they mean initial accuracy at room temperature. And when they say "stability", they mean maximum drift over temperature, meaning how much you need to mess with your clarifier.
 
CDX8412 said:
I'm wondering how that radio can achieve 32 watts of rf power output. It is a single final radio, correct?
Asuming it's not just a wild claim, how would you get that from this radio? Is this radio a 1969 or a MOSFET? I have just never seen more than about 20-22 watts out of a standard CB radio, and if you were getting that kind of power, wouldn't it likely be stressing the final transistor?
Just curious, and looking to learn something.
Click to expand...

All these numbers and stats to a run of the mill cb radio operator would be more like bells and whistles , for most ,the only thing that would stick in yonder head would be that 32.5 watts 8) IM with you here 8412 , 1969 or Mosfet numbers for sure. Although I have seen slightly bigger numbers but not 32.5 on a regular ole cb radio.
 
Al said it is how close on frequency the radio is . comming from the factory theyre usually about .005 and .0001 is what it measured after they did the alignment .
 
BOOTY MONSTER said:
Al said it is how close on frequency the radio is . comming from the factory theyre usually about .005 and .0001 is what it measured after they did the alignment .
Click to expand...

That would make it off by 27.185 Hertz on channel 19 which is 27.185 MHz. That's some pretty impressive numbers. I hope they were using a recent and well calibrated lab quality frequency counter or they would never have been able to obtain that kind of accuracy.
 
Switch Kit said:
CDX8412 said:
I'm wondering how that radio can achieve 32 watts of rf power output. It is a single final radio, correct?
Asuming it's not just a wild claim, how would you get that from this radio? Is this radio a 1969 or a MOSFET? I have just never seen more than about 20-22 watts out of a standard CB radio, and if you were getting that kind of power, wouldn't it likely be stressing the final transistor?
Just curious, and looking to learn something.
Click to expand...

All these numbers and stats to a run of the mill cb radio operator would be more like bells and whistles , for most ,the only thing that would stick in yonder head would be that 32.5 watts 8) IM with you here 8412 , 1969 or Mosfet numbers for sure. Although I have seen slightly bigger numbers but not 32.5 on a regular ole cb radio.
Click to expand...

Switch: I have to agree with you on the WILD 32.5 WATT'S.. I have an OLD PC- 76XL with the 1969 Final.. An that does 28 watts TOP'S... You got to love the Wild Watts story's..
 
I totally agree 667 and this is not to rain on BM's new radio ether. IM sure for the price he paid , he got himself a fine radio weather or not it's doing 30 some watts or not . Now , most AM radios I have been through over the years , usually would read something along the lines of say , 27.205.2 to say 27.205.5 but most would always read the point 2 . Dudmuck pretty much summed it up with his post. I hope you enjoy your new radio BM. :)
 
CDX8412 said:
I'm wondering how that radio can achieve 32 watts of rf power output. It is a single final radio, correct?
Asuming it's not just a wild claim, how would you get that from this radio? Is this radio a 1969 or a MOSFET? I have just never seen more than about 20-22 watts out of a standard CB radio, and if you were getting that kind of power, wouldn't it likely be stressing the final transistor?
Just curious, and looking to learn something.
Click to expand...
Yeah. ive seen 28 out of a 68xl but 32 WATTS I dont know about that.
 
sparkys told me befor i bought it that he could get about 32-33 watts out of it . i told him not to worry about squeezing everylast watt out of it because i want the radio to last and no one on the other end will know even 5 watts difference at that level . he said no problem that he'd take care of it . apparently 32-33 watts is what he typically gets from these radios doing what he does (what ever that may be) .
 
CDX8412 said:
I'm wondering how that radio can achieve 32 watts of rf power output. It is a single final radio, correct?
Asuming it's not just a wild claim, how would you get that from this radio? Is this radio a 1969 or a MOSFET? I have just never seen more than about 20-22 watts out of a standard CB radio, and if you were getting that kind of power, wouldn't it likely be stressing the final transistor?
Just curious, and looking to learn something.
Click to expand...


I regularly see 40+ out of radios like the 29 and 25, and 35-40 out of the Uniden equivalents. I measure power levels 3 different ways: Bird 4314B meter for carrier measurements, Wavenode system and an o-scope to confirm PEP levels. The Bird doesn't have the accuracy I like for full PEP measurements (only 8% of full scale), so I use non-mechanical methods to eliminate that inaccuracy introduced by the mechanical meter.

Those PEP levels do not stress the final, assuming your antenna is properly installed and tuned.
 

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