[ARC5] Are 1.415 MHz crystals available?

[Bill Cromwell]

Hi Charles,

Th best thing to do is put your signal generator on it and see if your 
IF strip will adjust that far. My own guess that it will. You won't have 
to modify anything to do it and if it won't tune that far you can just 
tune it back to 1415 kc. While you have the screwdrivers and frequency 
meters out see if your BFO will go that far, too. Let us know what you find.

I think the pair of converters and heterodyne oscillator for a filter on 
a different freuency is a messy approach, too. It does work - others 
have done it. Your idea will be neater.

73,

Bill  KU8H


On 03/06/2015 11:16 PM, Charles wrote:
> I'm interested in building a crystal filter for my 3-6 Mc. receiver 
> (1.415 MHz IF) in a ladder (Cohn minimum-loss) design.
> So I need four or five identical crystals at, or near, that frequency.
>
> Forget new, they're $36 apiece from ICM! Surplus Sales has 1.480 MHz 
> rocks for $5 but I'm not sure if the IF cans have that much retuning 
> range (I don't want to hack them up).
> The design gets more complicated if I up- and down-convert to more 
> readily available canned filter frequencies.
>
> Does anyone know if the IF can be returned to 1.480 without modifying 
> the L or C values?
> If not, are crystals closer to 1.415 available anywhere?
>
> thanks
> Charles
> WB3JOK/0