Ho Do I Configure: Demi L144-28 xverter and Flex 6600

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  • Updated 4 months ago
I have a Flex 6600.   I just received a Demi Q5 Transverter, L144-28  2 meter unit.
I have IF drive level:  0 to +20 dBm
Common IF.
Common TX/RX Antenna jack.
Keying:  PTT to Ground.

I have never used a transverter before, and wanted some help understanding some
items before I try to hook it up wrong.

A.  The included data sheet with the Transverter mentions sequencer steps 1 through 3.
I do not know what these are for.   Do you have to wire up something to the aux connector?

B.   I assume with common IF connector, I just run a good quality BNC 50 ohm cable
from the Flex 6600 Xverter-A port to the Demi IF port, right?

C.   I assume I should hook tx2 or tx3 output to the transverter and enable in SmartSDR radio
setup?  (I have tx1 to a HF amp, and tx2 to a shack xmit light.)

D.   Any pointers on setting up the Flex 6600 side configuration screens?

I do understand where to connect my 10Mhz reference.  I have an out-board GPSDO
and 10Mhz distribution amp.

I should mention that I am not using any special antenna or mast mounted pre-amp.
To learn a little about what is out there, I just plan to switch in the 2m/440 dual-band
base antenna I use on the my shack mobile rig.   I simply want to try monitoring for
some terrestrial/local SSB and simplex FM, and then try to see if I can receive a sat
downlink, even though a vertical base antenna may or may not get a short moment,
or simply not have enough gain.

Can any share or point to some tips or a wiring diagram?  Or simply reply and tell
me, per above, what else to connect where, and any "getting started" tips, so I can
learn without smoke?  Or minimal smoke :-)


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Neal Pollack, N6YFM

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Posted 4 months ago

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Photo of KF4HR


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I'm using a Flex-6700 with a different arrangement for 2M, but as for your Sequencer question.  The multi-step sequencer in your Demi unit is used to provide slight PTT delay(s).  One example might be to provide a PTT delay to allow a bit of time for a bypass relay to route transmit RF around a receive preamp before the PA is activated.       
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Larry - W8LLL

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All your assumptions are correct.
I have numerous Demi products and find I need to check transverter drive level
for each one to get the correct  output, I set them to the second from last bar on front panel light meter. You can either adjust it with the max power dbm setting or in memory settings. Sequencers will not come into play with your setup as described.

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John Swink

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I have recently added a Demi/Q5 L144-28 transverter with the same configuration to my Flex-6600.  Setting the RF slider to 100 (max) and the Max Power (dBm) to 1.4 (Radio Setup, Xvtr Tab), provides approximately 25 W from the xvtr.  The xvtr also drives a Toyko HP amp and with these settings provides approximately 300 W from the amp.  To key the amp, I built a breakout box that attaches to the aux connector on the xvtr and ran a line from aux pin 3 to the key line on the amp.  Unless you will be adding an external pre-amp or amp, you will not require the sequencer.

If you become interested in weak signal SSB, you will probably want to add a horizontally polarized antenna.