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Message-ID: <N7KJbAA7PIG8MwK1@telemetry.demon.co.uk>
Date: Thu, 13 Dec 2001 10:33:31 +0000
To: rsgb_lf_group@blacksheep.org
From: "Tom Boucher" <tom@telemetry.demon.co.uk>
Subject: Re: LF: Chips
In-reply-to: <3C17A882.3516A215@virgin.net>
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The other method is to use a phase-locked-loop: VCO at output frequency,
divided down to the source frequency, phase compared with the source,
phase comparator output controls the VCO via a loop filter.

This is a useful way of locking one frequency to another apparently
unrelated one which I have used successfully in the past and which of
course is the basis for a synthesiser. I used a CD4046 PLL chip with a
CD 4059 programmable divider but have no idea if these are still
available as it was about 25 years ago! Phase noise might be a problem
if you are looking for absolute spectral purity.


Tom, G3OLB

In message <3C17A882.3516A215@virgin.net>, Stewart Bryant
<stewart.bryant@virgin.net> writes
>Use three  push-push doublers in series.
>
>minicircuits do one, but the LF spec is 50KHz, so you might have
>to build a discrete one for the first stage (center-tapped transformer,
>two-diodes and a capacitor)
>
>Stewart G3YSX
>
>
>gii3kev wrote:
>
>> Hello All
>> There are numerious chips available for dividing frequency but what is
>> available for multiplying, eg.
>> I have a W & G freq generator  200 hz - 20 khz and want to use it for
>> 136 khz as a driving tx source. Is there a chip device that multiplies
>> this up to the desired freq.
>> say x 8 1600 hz - 160 khz.
>> I am trying to avoid the convential method with descrete components,
>> another approach would be to mix/hetrodyne it to the desired freq with
>> an appropriate xtal osc cct.
>> All advice appreciated.
>> 73 de Mal/G3KEV
>

-- 
Tom Boucher
Telemetry Consultants Limited
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