Paul, Most of my xverters are Demi up to 10ghz and I like them for few
reasons. They hold up well mounted topside, they are very stable with the
Apollo board and support is excellent. The micro-lo does drift esp outside
but the xtal control
does have a plus, it is clean. All the synthesizers I have used are not and
can cause havoc if you have close by ham neighbors. For that reason I do not
run my 432 beacon with syn boards instead I am using a clean transceiver
that seems to hold freq
within 100hz. Of course you can spend some more $$ and go with a Kuhne but
should it break it will take a long time to get fixed not to mention
shipping charges.
I just purchased a couple of transverters from the Transverter Store,
http://transverters-store.com/ and would not recommend them. One was
unusable and the other required a preamp. Both LO's were way off freq. The
best I can say is they came
in a nice enclosure. It is a cheap way to get on the air but you get what
you pay for. Cheap price, Cheap product. Check out the complaint on the net,
I should have. I would not put them in the decent category let alone the
awesome one.
Before you spend more $$ I would talk with Steve at Demi and see if he has
any suggestions.
73'
Steve
Steve,
I may have missed something last time I checked but it looked like
DEMI had options to cure drift in that manner for 450 MHz and down,
2.3 GHz and up, but nothing for 903/1296. The ZL2BKC board seems to
fill the gap. While the various phase locking solutions seem fairly
priced for what they do, it can be the straw that breaks the camel's
back for those who arguably shouldn't be contemplating these bands
in the first place. :-)
I decided my $25 crystal heaters probably can't do much for the
Micro-LO which is why I pushed the DEMI onto the more-or-less-reject
pile. Nothing against DEMI, just not a good option for me with that
much drift. It remains to be seen what I can do for the old UHF
Units but hopefully I can improve it somewhat.
73,
Paul
On 04/25/2018 07:47 AM, Steve(K1IIG) wrote:
PAUL,
The Demi Micro-Lo is notorious for drift which of course they have a Syn
board you can replace that requires 10mhz to lock it. You can buy an
10mhz
OCXO for $10 on the internet that will work fine to lock it.
Take a look at this site https://zl2bkc.com/ which also has a replacement
board for the Micro-Lo.
73
Steve
--------------------------------------------------
From: "N1BUG" <paul@n1bug.com>
Sent: Wednesday, April 25, 2018 3:20 AM
To: "VHF Contesting" <vhfcontesting@contesting.com>
Subject: Re: [VHFcontesting] What separates a decent transverter from an
awesome transverter?
One thing I didn't see on your list that always concerns me is LO
drift. Drift can be a problem for any weak signal work, say a long
haul CW sked during a contest. If you want to do some of the digital
modes it can become a critical issue, even a show stopper.
Since I can neither afford nor get my head around the complexities
of GPSDO locking, I am always concerned about crystal oscillator
drift in transverters. Usually I do the best I can to build and
install some type of crystal heater... with mixed results over the
years.
Sometimes I find things that surprise me. Last summer I measured
drift on two 1296 transverters: a relatively ancient UHF Units and a
relatively newer but not current generation DEMI, both as yet
unmodified. Over a temperature range that caused the DEMI to drift
over 6 kHz, the UHF Units moved just a bit over 200 Hz! I know which
one I will be using if I ever get the rest of the stuff together for
1296.
Paul N1BUG
On 04/24/2018 10:31 PM, Patrick Thomas wrote:
Hey all,
Subject more or less says it all... I guess better sensitivity,
lower noise, better selectivity, and better linearity are the
essentials in vague and relative terms, but what attributes do
you look for in a REALLY GOOD transverter?
Or for those who have gone further into making them... what
components, construction techniques, etc., make a difference?
Partly this is a question I hear a lot and only have a vague
notion of how to answer other than "obviously the expensive ones
are better... somehow." :)
And partly it is a request for topics for self-guided
study/experimentation as I attempt my own homebrew projects.
Many thanks,
Patrick - KB8DGC
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