[ARC5] programable crystal oscillators

[Robert Nickels]

On 4/23/2017 12:34 PM, Paddy Ryan wrote:
> .I take it if you want 1415khz (for an ARC bfo e.g) you cannot get it 
> by ordering 1.415 MHZ or can you?.

Sorry for the confusion, Paddy.   DigiKey's people must enter the 
frquency in MHz, so if you give them KHz, it requires them to delay your 
order while they call or email you for correction.

Thus,  if you want 1415 KHz, simply specify the frequency as 1.415 
Mhz.   For 6800 KHz, specify it as 6.8 MHz, etc.    Since the lowest 
frequency available with these parts is 1.0 MHz, if you wanted something 
like a .455 KHz signal for a BFO, you might buy an oscillator programmed 
for 4.55 MHz and divide the output by 10, or as in one little radio I 
recently did, use a frequency in the 2.275 MHz range and divide by 5, 
since the old reliable 7490 decade counter contains a divide by 5 
counter.   Lots of ways to go, but you'll need to wire up the external 
circuitry needed and be mindful of spurs or harmonics that may result.

It's no problem to specify frequencies to 100 Hz precision needed to 
generate an on-frequency SSB signal for example.  Just be certain of 
what you give them because these devices are not returnable after they 
are programmed.

73, Bob W9RAN