[RTTY] ARRL RTTY

[Richard Ferch]

Jeff AC0C wrote:

> Can you explain to the uninitiated how a dual RX configuration would provide 
> an advantage?

I'll be bold enough to add to what Ed said on this:

I use a radio with two receivers (a K3), but only a single antenna (a 
multi-band vertical), and have found several advantages over a single 
receiver, at least in RTTY.  I don't have to worry all that much about 
marginal print, because if I can't copy someone, they can't usually copy 
me either unless their antenna happens to be just as inefficient as 
mine, so I was pretty much in the situation that Ed described.

In no particular order:

1. With the two receivers on different bands, you can populate the band 
map on the second band while the radio is receiving on the first band. 
Even when you are running you spend more than half the time in RX; 
assuming you can read faster than RTTY can send, there is plenty of time 
to read and click on signals in the second window while still keeping 
track of the first window. You can also click on a previously-received 
call sign in the second window while you are transmitting from the first 
one, i.e. mouse-clicking in the second (receive-only) window does not 
have to take any useful time away from the first window. When you 
eventually QSY the transmitter to the second band, you can pick off the 
stations you stored in the band map one after the other without taking 
time to tune them in and wait to see if each one is a dupe or a new 
station. Until you exhaust your list, this can give you as high an S&P 
rate as if you were using the cluster, even though you do not actually 
have a cluster connection.

2. With the two receivers on the same band, you can do the same thing on 
a single band.

3. If your radio and software support transmitting from both VFOs, you 
can S&P on different parts of the band with the two VFOs and work 
stations as soon as you find them on either VFO. You can keep on tuning 
on the other VFO while you are receiving the exchange on the first one. 
Transmitting from the second VFO does slow down your S&Ping on the first 
one (unlike SO2R you have to wait while you are transmitting), and the 
timing does not always work out between the two VFOs so that you have to 
wait through an extra QSO on one VFO because you were working someone on 
the other one, but it's still a lot better use of your time.

4. If you are sitting in a pileup on a rare multiplier, you can keep 
right on either spotting stations to the bandmap or out-and-out S&Ping 
from the other VFO elsewhere on the band. You might have to forego 
calling into the pileup a few times while you work on the other VFO, but 
on the other hand the time spent in the pileup is not lost.

5. You can run and S&P simultaneously on the same band. When you find 
someone to work on the S&P radio, you take time out from CQing for just 
long enough to work the S&P contact, then go back to CQing. You can't 
interleave contacts the way you could with two radios on two bands, 
because you can't receive while you are transmitting, but on the other 
hand you can do this using only one antenna or on only one band, which 
you can't do with SO2R.

6. If you are a little pistol who always has to take several tries to 
get through to the other station, you can sometimes call two stations at 
once, alternating between VFOs. The timing has to be right for this - 
when one station comes back to someone else, then if the timing is right 
you can call the other one, and when he answers someone else, you go 
back to the first one and wait for his QSO to finish, etc. I sometimes 
even found myself watching two guys CQ in my face at the same time, but 
at least I could write off the stations who couldn't hear me twice as 
fast as I would have with one VFO!

The downside: during the times I was doing this I didn't have time to 
surf the Net, read my e-mail, etc.

Thanks for the contacts in the Roundup.

73,
Rich VE3KI