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tweaked and peaked?

peaked radio

well, being a guy with a peaked radio, i would say its woth it, unless its a cobra19 or something crappy like that.
 
This requires a good, calibrated frequency counter, which requires money, both the initial outlay AND periodic recalibration.
Click to expand...

I have one :) :) ...but honestly I do need to get it calibrated, although I really doubt it's off all that much...

Oh wait, I'm not a CB tech LOL
 
Would you rather have precision or accuracy?

I have a lot of custom, high quality 10MHz OCXOs with ageing specs of less than 1Hz/year.

I was considering building some reference standards calibrated to the GPS frequency reference if there was any interest.
 
bob85 said:
whats the difference between precise and accurate?
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Precision is a measure of repeatability.

Accuracy is a measure of how close to the actual value.

Think of darts:

Precision means that you have a very tight grouping, the dart hits the same spot every time, even though it may miss the bulls eye.

Accuracy means that the dart is close to the bulls eye, it might even hit the bulls eye every time, but it may have a wider grouping than above.

You can make a similar analogy with time.
 
One then ponders, do I want an instrument with greater precision or greater accuracy?

Would I pick the one that has a precision of say +/-5Hz or the one with an accuracy of +/-5Hz?

Hmmm :?

:idea: :arrow:
 
here are some of the specs of my off air standard i would like your opinions?

any time i have a lock onto droitwich my long term stability is 2x 10 exp-11 npl traceable or close to as accurate as the ceasium rubidium controlled transmission monitored by the national physics laboritary to which it is locked onto or so they claim,
short term stability typical 4x10 exp-9 one second

when i cannot get a lock ( never happened yet ) the accuracy of the internal ovened standard is 5x10 exp-9,
it has 1, 5, and 10mhz outputs plus a presettable output in .0001hz steps from 1khz to 16mhz,

i can and have checked it against a couple of new gps based standards from the same maker anytime and both off air and internal oven are well within specs,

ps, i use the off air standard as the referance oscillator in the counter rather than use its own internal oven,

not the worlds most accurate i know but its good enough to see that all radios and most counters unless they have a very good oven will drift about all day long :wink:
 
When I write a specification, I require "maximum error must not exceed 0.2 millivolts" (or 3 per cent, or 75 parts per million...). I always try to specify it clearly, in easily obtainable terms.
 
bob85 said:
any time i have a lock onto droitwich my long term stability is 2x 10 exp-11 npl traceable or close to as accurate as the ceasium rubidium controlled transmission monitored by the national physics laboritary to which it is locked onto or so they claim.
Click to expand...

You know the answer to this. You cannot argue with the standard.

bob85 said:
the accuracy of the internal ovened standard is 5x10 exp-9
Click to expand...

This looks like precision spec. and would indicate how much the frequency could change, usually over a specified period of time. Once you loose lock to the off air standard, you don't know how close you actually are to being on freuqency, unless you have a means to calibrate the internal reference, which you might. At least it looks like you have the means. But as long as you're always locked, it don't really matter.

If I may make another analogy--you are digging ditches with a surgeons scalpel.

But then, I was looking into doing the same thing in building a GPS disciplined reference.
 
sorry beetle you are right i just found the paperwork,

long term stability better than +/- 2 x 10 exp-11,

short term better than +/- 1 x 10 exp-8, typical +/- 4 x 10 exp-9 one second, 0-30 degress centigrade

:)
 

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