[600MRG] 630 meter Kits, and Transverters

[John Molnar]

Hey Guys!

I wanted to add a few comments regarding converters, transverters and the
like.

Check the specs carefully on the mixer device you choose.  For example, an
old standard like the Mini Ciruuits SBL-1.  NOTE that the RF and LO ports
are rated from 1-500 MHz, while the IF port is DC-500 MHz.

Thus the 'standard' convention of driving the RF port with a signal at 137
or 475 kHz is going to result in a significant performance hit.  However,
there is no problem in reversing the roles of the IF and RF ports ... The
output of the front-end (antenna, LPF, preamp or whatever) can drive the IF
port (rated to DC) and the mixer products are presented at the RF port.  LO
remains unchanged.

Most mixers are rated for a 50 ohm load at all ports and failure to match
can result in poor performance.  I guess it depends upon how crazy you
really want to get...and what you can live with in practice.

The receive converter at XKA was designed considering the above and can be
seen here: https://wg2xka.wordpress.com/receiving-2/       .

John ETD / XKA

On Wed, Apr 13, 2016 at 9:51 PM, dick.bingham <dick.bingham at gmail.com>
wrote:

> Greetings All !
>
> What has worked well for me is to use a 10MHz local oscillator signal to
> feed a doubly-balanced mixer (DBM) plus a transceiver capable of tuning
> from 10.000MHz to 30MHz (or higher) to listen to MF signals
>
> I connect an antenna to the RF-Port, the LO to the LO-Port and IF-Port to
> the receiver input and copy DC-to-1.000MHz directly on the tranceiver as
> 10.000 to 11MHz. Just subtract 10MHz from the tranceiver readout to know
> what base frequency you are hearing.
>
> All of this works OK for me on receive without filters between the antenna
> and the mixer mainly due to no strong local signal sources within
> ten's-of-miles. A BPF for your frequencies of interest probably will be
> needed.
>
> This same scheme will work well for transmitting. A few milliwatts of TX
> RF from your tranceiver (with 10dBm of LO), some BPF's to keep things
> "clean" plus an amplifier chain to achieve the output power level you
> desire, and you are on-the-air.
>
> That is about as close to a "kit" on 630-meters as you can get these days.
> . .
>
> 73 Dick/w7wkr CN98pi
>
>
>
>
> ---------------------------------------------------------------------------------------------
>
>
>
> > On Apr 12, 2016, at 7:16 PM, J Mcvey <ac2eu at yahoo.com> wrote:
> >
> > Heathkit rebounding? Their site looks like a half baked yard sale of
> unsaleable 70's leftovers at crazy prices.  Don't hold your breath waiting
> for something worth having from them!If you don't like the dongle SDR
> radios, I'm sure there is an article about MF converters from QST or an
> offering on some Ham's website if you google it.There isn't much to it.
> Basically a converter/mixer stage designed to heterodyne 479 KHZ to maybe
> 1.8 MHZ just like they do in the superhetrodyne receivers.
> > A google search yielded this:
> http://www.amrad.org/wp-content/uploads/2015/09/AMRAD_Low_Frequency_Upconverter-1.pdf
> > A bit overdone, IMO, but you get the idea...
> >
> >
> >
> >
> >    On Tuesday, April 12, 2016 9:45 PM, Alan Cooper <w7aln at netzero.net>
> wrote:
> >
> >
> > Hello..!
> >
> >
> >
> > On the topic of a lack of gear for MF I put a bunch of idea's in the
> slowly
> > rebounding Heath Kit company
> >
> > Of offering such a thing on the basis that it would put them in the
> middle
> > of a historic event of Ham
> >
> > Radio's return to the Place in the spectrum where it all started. They
> have
> > not replied but I did not
> >
> > Really think they would respond with much. But perhaps if more of us put
> > this suggestion in their ear?
> >
> >
> >
> > Alan Cooper
> >
> > w7aln at netzero.com
> >
> > Bandon, Oregon
> >
> >
> >
> > Morse Code Forever! the original digital that started it all
> >
> >                                           AKA CW (circa 1880's)
> >
> >
> >
> >
> > ____________________________________________________________
> > Affordable Wireless Plans
> > Set up is easy. Get online in minutes.
> > Starting at only $9.95 per month!
> > www.netzero.net?refcd=nzmem0216
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> >
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