Duane speaks absolutely correct about the transverter issue. There is a
difference in transverters and the receiver, as the IF, makes a difference
too. It is sure nice to have a very quiet, stable receiver with very narrow
filters for weak signal VHF CW and SSB work. The all mode, all band radios
just don't seem to get it, especially in the receive department. And if you
are in a high RF area, forget about adding a pre-amp. That just spells more
trouble. NF is the game to be played.
I opted to spend my money on a couple of high performance transverters in
place of a Tentec 6N2 rig. I'd like to have a 6N2 but when there's only a
certain amount of $$$$ then I have to choose where they get most effectively
spent.
If anyone needs info on "how to feed" a transverter, let me know. I'll be
glad to share info that works and is simple.
73
Bob K4TAX
----- Original Message -----
From: "Duane Grotophorst" <n9dg@yahoo.com>
To: "Paul DeWitte K9OT" <k9ot@mhtc.net>; <TenTec@contesting.com>
Sent: Saturday, September 07, 2002 10:56 AM
Subject: Re: [TenTec] transverters on 6m
>
> --- Paul DeWitte K9OT <k9ot@mhtc.net> wrote:
> >
> >
> > I know that there several on this reflector that use
> > transverters for vhf. I
> > am wondering how they would compare to the 6n2 rig.
>
> If you are going to be using a Jupiter as an IF radio
> it would be reasonable to expect similar overall
> performance to the 526 since they share a certain
> amount of similarity. The main difference between the
> 526 and the transverter route is dynamic range
> performance. The Down East Microwave and SSB
> Electronic transverters have 3rd order intercept
> points in the mid to high 20's (though actual
> performance is ultimately dependent on the IF radio).
> I believe that 526 is somewhat less than that that. If
> the IF radio is an Omni V or VI you should then expect
> to see its performance traits on 6M as well, as long
> as the transverter in front of it is up to the task.
>
> > Using a transverter how
> > much power out will you have?
>
> I believe that the Ten Tec 1208 will do about 8W with
> 3-5W of 20M drive. The Down East Microwave 50-28 will
> do around 15-20 W out; I seem to be getting about 16W
> out of mine. In its basic configuration it will accept
> a max of 200mw of 10M drive so it requires a low level
> drive signal, or the "common IF" option. There are
> also transverters from SSB Electronic that will also
> do about 20W out and have drive requirements similar
> to the DEM units. The SSB electronic transverters do
> perform somewhat better than the DEM units and are
> much more polished cosmetically. The DEM 50 - 432 MHz
> transverters are in plain (unpainted) die-cast Bud
> boxes and are nothing special to look at. The big down
> side of the SSB Electronic transverters though is that
> they are very pricey.
>
> > Are they 10w and then
> > you have to use an amp
> > or what?
>
> 10W will work a lot of stuff when the band is wide
> open, ... and you have good feedline plus a modest
> beam. Where the extra power comes into play is
> extending the no propagation range of your 6M station.
> If you have to choose where to put the money, put it
> in the feedline and antenna first before the amp. That
> way you'll hear more stuff that you can't work which
> will then in turn drive you into buying the amp
> anyhow!!
>
> > Are the filters better in an Omni V or VI
> > better than most 6m rigs?
>
> Definitely, especially if you are referring to the
> common 70's and 80's vintage all mode mono-band
> radios. For the 526 I would expect to have very
> similar filtering characteristics to the
> Pegasus/Jupiter series radios. So it should handily
> outperform the all mode mono-band radios from the past
> as well.
>
> > I guess I am wondering what the advantage of using a
> > transverter is.
>
> I started out with the various mono-band and dual band
> all-mode import rigs for VHF/UHF. Then I bought a DEM
> transverter to get onto 222MHz with (580 Delta for the
> IF). I was instantly converted to the transverter
> concept; I was amazed at how the signals would just
> stand out from the background noise. I've since gone
> to a DEM transverter for 6M, again it is the way that
> signals stand out from the noise that I find so
> impressive. One of the key parameters to look at if
> going the transverter route is its noise figure, the
> Ten Tec 1208 came in at 7.3dB in the ARRL test DEM
> claims 1dB or better for the 50-28, the SSB Electronic
> LT6S is also 1dB. When I set up the my transverters I
> set their IF output gain so they add a just
> perceptable increase in RX noise when turned on (done
> with a 50 ohm load on the transverter antenna
> connector).
>
> Also as a side note, the ARRL has not done any reviews
> of the current DEM offerings so none of the ARRL
> reviews actually reflect the performance of the newer
> DEM units after mid 1997 or so. In the case of 6M what
> was reviewed in Feb 1997 QST is not what is currently
> shipping and is a different animal despite having the
> same model number.
>
> Duane
> N9DG
>
>
> Reference URL's:
>
> http://www.tentec.com/Tk1208.htm
> http://www.downeastmicrowave.com
> http://www.ssbusa.com/ham.html
>
>
>
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