[Lf] [Fwd: LF: Re: Oscillator Stabilty for QRSS?]

[Andre Kesteloot]

Dave Brown wrote:

> Hi Steve
> I suggest you take a look at the following URL- it is VERY inexpensive and I
> believe will do everything that you could possibly want.
>
> http://www.qsl.net/zl1bpu/
>
> Go down a couple of layers on Murray's web page through 'micrprocessor
> projects' then the 'synthesised 1 watt LF exciter' to get to the relevant
> info.
>
> 73
>  Dave
> ZL3FJ
>
> ----- Original Message -----
> From: "Steve McDonald" <jsm at gulfislands.com>
> To: <rsgb_lf_group at blacksheep.org>
> Sent: Wednesday, August 14, 2002 6:56 AM
> Subject: LF: Oscillator Stabilty for QRSS?
>
> Perhaps someone who has already 'been there' can offer their advice.
> I would like to start building the exciter stages for what will be my 136KHz
> tx (hopefully we will have access to the band within the year!). The DJ1ZB
> exciter (modified by DF3LP) is the circuit that I am questioning. It mixes
> two xtal controlled 4MHz oscillators, 136 KHz apart, to extract the 136KHz
> signal. Can I build two VFO's, somehwere around 1MHz and set them 136KHz
> apart, that will  be stable enough to handle QRSS work? I am worried about
> drift but also thinking that they may be stable enough if kept in the 1 -
> 2MHz region. As well, they should (if identical) drift by the same amount
> and thus be self-correcting? Is this a reasonable avenue to pursue or should
> I just break down and buy a couple of xtals??
>
> Steve / VE7SL  Mayne Island, BC