Ok Warren,
Yes ..its not the dds , but the rock that runs it hihi , first one i saw in
use was fed with nearly 1 ghz clock , before the ppl clock systems .. dont
think the ppl systems wander .. but do seem to produce more 'spurs .. all
my kit is conventional xtla ref /ppl , this vfo is run some old xtal
controlled marine equipment mf/hf .. so will be behind quite a few tuned
cct's
(you should of seen the traces from my 4 mtr (70 mhz) wspr tx a while
back .. now that was drift)
tnx- G ..
This one seems to fit the bill , link from Gerhard ,
http://www.box73.de/catalog/product_info.php?cPath=112_115&products_id=119&osCsid=9nk30edle1v6k0oooub8e4fjs2
--------------------------------------------------
From: "Warren Ziegler" <[email protected]>
Sent: Wednesday, May 13, 2009 4:48 AM
To: <[email protected]>
Subject: Re: LF: Low freq DDS VFO any ideas / for sale etc ?
Graham,
Be aware that some of the available DDS kits use a
non-temperature compensated reference oscillator and may not be
suitable for longer duration QRSS work unless you take care to keep
them in a constant temp environment.
I ran an inexpensive DDS driving my 137kHz transmitter, and you could
tell when I turned the thermostat up or down in the hamshack by the
direction of drift of my QRSS 60 signals!
The worst case was when I had it sitting in a rack above my
oscilloscope, you should have seen the drift after using the scope and
turning it off!
--
73 Warren K2ORS
WD2XGJ
WD2XSH/23
WE2XEB/2
WE2XGR/1
On Tue, May 12, 2009 at 5:25 PM, Graham <[email protected]> wrote:
Looking for a low frequency , 100k > 30 Mhz ish dds vfo, possibly a kit ,
better a part completed kit would be better ...second hand working
even better !
Ideal would be a box with a frequency display and a key pad to
enter the frequency , preferable to a pc addressed device
Couple of volts sine wave out , nothing fancy , simple master
oscillator for tx
Any ideas or links (any for sale ?)
Tnx- Graham .
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