Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

frq. tolerance ??

I dont think it's been established what final is in his radio ? shouldn't be to hard to find out though , open it up and look . IF DTB say 40 watts out of a stock final ? I've totally lost it here ? it's not going to happen , especially not in his or others perfect worlds. As I said before , I've seen more on some , but nothing over 30 watts pep ! NOTHING ! close ,but that didn't even count in the perfect world , it was clipped , anti-spiking diode was jumped and the pots were up or out as far as they could go. You can use all the fancy dancey meters you want .(You wouldn't even see those numbers on a Bird 43P calobrated PDC 600 !) Unless it's a mosfet or 1969 , it ain't going to happen in a perfect world concerning a Uniden 78LTW or any other AM only CB Radio. Now all of a sudden IM missing something here DTB ? You would be one of the first ones to rip my head off in any debate about what does what here ? Remember this DTB - over the years , it's guys like you and Freecell whom have taught me right from wrong on a lot of this crap and why , weather or not I follow directions or not , I would personally hate to think you were going against your own grain here ? ;) Also , I do realize you have stated in the past that you would like to strangle me for some of my posts , but trust me here dude , I honesty come from the heart here. Happy Holidays to you and your's. Peace
 
DTB Radio said:
Those levels are seen with 1969 and MOSFET finals. The MOSFET's seem to generally do better.
Click to expand...

MOSFET Finals.. Well do better.. And your seeing a lot more MOSFET Finals in AMp's also.. Why?? Thats's for another day..
Tom
 
Don't forget, you put a radio on the bench with a thick short power cord and give it a steady 14.7-15 volts with no drop off and you will maximize your wattage.
 
One thing I was wonderin, when you look at the TDS and the Po figure is 16W min, 18W typical...I guess that means that you are just about guranteed an 16W CW output, so I could then set my rig to a 16W dead key and tune for classic 100% modulation and get an instantaneous peak of 64W.

But I could never get more than 28W peak without modding the circuit for more loopback voltage and what not...IOW, down and dirty...

So I'm quite happy with a 6-7W high dead key and leave the mod at 100%, and with a slightly sub 1W low dead key with fair swing.

BTW, time accuracy: you can set a $5 casio to be accurate to the picosecond, but the question is, how long will it stay that way? The way I read the spec is that 0.002% means that not matter where you set it, it will move around that much, ~550Hz
 
the standard for frequency tolerance (not frequency stability) in a class d cb transceiver is + or - .005% of the operating frequency in question. @ 27Mhz.. that's 1.350Khz..

for 27.185 the channel limits within that specification would be 27.183641 - 27.186359, recalculated for 1.359Khz. @ 27.185, rounded to the nearest hertz.
 
in the context of the question, I do not see how uniden words their spec.

the stability numbers I've seen are 0.001%, which is how much it's gonna float around...

tolerance is 0.005%...goodie, so they can set it to +/-1359...

kinda nice cause that is over half the frequency response range and exceeds the clarifier range...

The WorldWide Radio Forum Forum Index » CB Radios »

The point was that it is going to float around more than what they are saying they set it too...

But it's fun...I fire up my OCXO time base standard and get it phase locked to the GPS reference, then I calibrate my CB with the referenced HP counter set to 0.1Hz resolution and fiddle with it til it's +/- 1Hz...takes about a day or two...
 

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom
      Back