Simon Luttrell
2021-08-18 23:37:51 UTC
snip |
Great idea Gary, but it defaces the rig. No help when bowwowing Joe's
rig on field day. An easy fix is to make up a small buffer amplifier
using a single transistor, e.g. BF981 or a modamp, operating in a linear
mode (most important) to boost the low power to about 20mW. Then add a
filter on the output to ensure a clean drive.
A level setting pot is a good idea as well so you can adjust the power
input to the transverter, and while you are at it, a relay and two
sockets to switch the receive line and the signal to the transverter
pin on the acc1 connector.
Now you can leave the rig wired for HF and have the transverter
connected. Change bands at the flick of a switch and protect the
transverter from 100W of HF.
73 Mike
Well, you can certainly do that, Mike. But 1) I don't consider addingGreat idea Gary, but it defaces the rig. No help when bowwowing Joe's
rig on field day. An easy fix is to make up a small buffer amplifier
using a single transistor, e.g. BF981 or a modamp, operating in a linear
mode (most important) to boost the low power to about 20mW. Then add a
filter on the output to ensure a clean drive.
A level setting pot is a good idea as well so you can adjust the power
input to the transverter, and while you are at it, a relay and two
sockets to switch the receive line and the signal to the transverter
pin on the acc1 connector.
Now you can leave the rig wired for HF and have the transverter
connected. Change bands at the flick of a switch and protect the
transverter from 100W of HF.
73 Mike
a jack to the back panel "defacing" the rig, and 2) if I'm borrowing
the rig it only takes a couple of minutes to remove the cover and move
the transverter cable over to the pre-driver output jack, and another
couple minutes to put it back when I'm done. No *permanent* changes are
required. This is the quickest, easiest, and cheapest way to allow the
IC735 to work with 10mW input transverters.
I'd use an external box only if it were imperative that neither radio
nor transverter be touched internally. In that case, your idea is an
excellent one. I'd likely use a MAR-4 as the gain element. Note that
you *could* tuck one of these *inside* the 735 or *inside* the transverter
as alternatives. That wouldn't "deface" either piece of equipment, and
eliminates another external box and another level of TR sequencing.
If you're using transverters with a transceive IF port, the best place
to put the extra amp is inside the transverter on the Tx side *after*
the transverter's internal TR. If you're using a transverter with a
split IF, many are this way, then putting the amp in the radio to bring
it up to "standard" transverter levels might make more sense. Especially
if you want to mast mount the transverter, then having the hotter signal
at the other end of the coax becomes very attractive.
There's nothing *wrong* with your approach, it is just that I'm reluctant
to build yet another box when I don't have to. That's just more stuff you
have to lug along, and another set of cables to add to the tangle, and
possibly cause problems, and another level of TR switching to sequence.
Gary
--
Gary Coffman KE4ZV | You make it, | Due to provider problems
Destructive Testing Systems | we break it. | with previous uucp addresses
Lawrenceville, GA 30244 | |