[NLRS] The road to 10 GHz

Mon, 19 Aug 2002 20:53:27 -0500

Jon, good summary.  I have one thing to add.

The DB6NT transverters I have for 10 Ghz (3 units) all put out 300 mW even
when speced at 200 mW.  The datasheets signed by DB6NT himself indicate the
300 mW and my power meter also confirms.  I spoke with Gerry at SSB
Electronics about this and he said the last few batches have been higher
than 200 mW.  Get lucky?  Maybe.......Ask and make your own luck I say.
Squeaky wheel gets the grease.  300 mW does a bit better than 200 mW I would
say!

73

Good luck in your descision.  I love the demi stuff, but I really think the
DB6NT is the way to go if not starting with any power amp option.

Mike - KM0T

----- Original Message -----
From: "Jon Platt" <[email protected]>
To: <[email protected]>
Sent: Monday, August 19, 2002 8:15 PM
Subject: [NLRS] The road to 10 GHz

OK, here is a short summary of the email replies that I received regarding
various ways to get on 10 GHz narrowband.

DownEast Transverter:   Specs are 10 mW output with a receiver NF of < 2 dB
for a cost of $395.   For $50 more you get the SMA t/r relay and the
appropriate t/r relay driver hardware.  This same product is available in
kit form, but I noticed that the specs are derated to 5 mW output with a < 4
dB NF for the receiver.  Kit price is $275 and the SMA t/r relay option is
not available.  Ed, MNK, has reported that he has built two of these kits.
He reported that soldering the pipecaps was easy by using a hotplate.  He
thought the harder part was peaking all the filters and "the large number of
SMT components".  His summary is that the cost savings is not worth the
effort although he did learn about what does & does not work at 10 GHz.
DownEast also offers a 2 watt power amp for $350.

DB6NT Transverter:   The "new" MKU 10 G2 10 GHz transverter offers a 1.2 dB
NF with 200 mW output.   You need to do your own t/r switching.  The price
from SSB Electronics is $580.   The same product & specs is available in kit
form for $385.  Matt, KF0Q, is working on the kit version and reports that
the board doesn't fit in the "tin box" without trimming and that getting the
board soldered to the sides of the box has been difficult.   Matt reports
that there is "much less to do than a typical DEM unit" on the plus side.
Also, only a DVM is required for test equipment, but access to a microwave
power meter is helpful.   Matt indicates that the DB6NT instructions could
be better.   On the plus side the unit is very compact and simple (about
2"x7"x1").   Matts work is still a work in progress.   Marc, N8KWX, has also
built this kit (about a year and a half ago).  On the up side, Marc notes
the great NF (1.0 dB), its relatively stable, and 200 mW's output (using a
FT817 IF rig and a 18 dB horn he has worked 90 miles to Bob, K2YAZ).   The
200 mW's output is a good power level to get started with as its 13 dB over
10 mW while only 7 dB under one watt (a Qualcomm PA could be added later).
Marcs thoughts is that the DB6NT transverter may be easier to build than the
DEM, but that you should be an experience kit builder.   SSB Electronics
does offer a DB6NT 1w and a 2w PA for $340 and $470 respectively.

Qualcomm:   Chuck, WB6IGP offers a "kit" (my term) based around a Qualcomm
unit (commercial equipment) that is modified by you, the kit owner,
following the established instructions.  You need to check out the San Diego
Microwave Society web site at http://www.ham-radio.com/sbms/sd/ to find the
technical papers on this modification (which includes some excellent
pictures of the modifications that are need to make the Qualcomm stuff work
on 10368).   What is offered is what they call the lamb chop board that
provides about 10 mW output after the mod for $100.  In addition, the lamb
chop board requires a 10 MHz TCXO which you can purchase from Chuck for $10,
so, for $110, plus some work at the bench, should provide you with a quality
10 Ghz transverter (for $110).  A 1w PA is also sold for $55 that also
require modifications.   If you are interested, my suggestion is to check
out their website.   Jon, K0FQA, has recently purchased this kit and plans
to do the needed modifications this winter.

Hope this summary was helpful.  Thanks to Matt, Marc, Ed, Jon, and others
that I may have missed for responding to my original email on this topic.

73, Jon
W0ZQ.

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