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XR0Y on 40m RTTY














Ok, that was pretty cool. Several firsts in that QSO. 




  • XR0Y on 40m


  • XR0Y on RTTY



  • RTTY contact with Linux


  • RTTY contact with MMTTY with Linux


  • RTTY operating split


That Q took 40 minutes to work. It was especially hard because there was a CW contest
operating right next to where I was trying to listen for XR0Y.



73 de NG0R in EN25ue.





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Shunt Loaded Towers

Today I finally finished the tune-up on the 80m shunt.



I have had a shunt on my VHF tower for a couple of years. It seems to play ok. In
the past I have used door knob capacitors to get it into the ballpark. The challenge
is that then the antenna is locked to a small portion of the band. 80m is a big band
from 3.5mhz-4mhz. That is big place.



Earlier this year I decided that I wanted to able to use the antenna in the bottom
of the band 3.525-3.585mhz for CW, RTTY, and PSK in addition to being able to work
the DX window for SSB up around 3.8Mhz. Additionaly I did not want to have to use
a tuner since I like to build QRP rigs which do not normally have a tuner so I need
a decent match.



The answer was to use a biasT to power a remote relay at the feed point that allows
me to switch between two variable capacitors. One is tuned to the CW portion of the
band and the second one is tuned to the SSB DX window. A simple flip of the switch
from the shack and I can now move from the bottom of the band to the top and I am
back in business. (No running outside in the winter with my analyzer to retune it
i the dark.)



Thanks to N0FP for helping design the biasT network on a piece of paper and letting
me borrow some junk box components. He also provided me a nice spreadsheet a couple
of years ago that helps to figure out the turns ratio for winding transformers. I
wound a custom transformer to help get the feed point between 50-75 ohms. This is
my third generation feed point and I am extremely happy with the results.  (I
also have a shunt for on 160m on the taller HF tower.)



The magic:

On/Off switch + BiasT + relay

Two variable capacitors roughly 75-150pF each

A custom wound transformer for the feed point impedance match

A custom wound balun



Please ping me if you would like more info or pictures.




73 de NG0R in EN25ue





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Montserrat on Topband






VP2MXO is my first top band DX contact of 2009. A little rough for both of us but
it made it into the log.



I am trying to keep up the pattern of at least one QSO per day... more is better,
one is enough. (I have to admit that N0FP and I were talking on topband at less than
1 watt tonight for almost an hour but that is chip shot from here.)



73 de NG0R





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DP1POL ANTARCTICA - In the log!






Woohoo!   Felix uploaded his log tonight. A couple of hours after working
him on 40m I found that it was already online. To be honest I was a little worried
that he did not copy my callsign correctly. The band conditions were very poor.




I am very excited. I have been wanting to work someone down there for many years.
At my old QTH (home) the RF noise was very high due to the fact that I was in a large
metro area. At our new (4 year old) QTH my noise level typically S0 or S1 especially
in the winter period for North America. There are Q's like this that I just could
not make at the previous QTH. I have been talking with my 3 boys about trying to make
a Q with the South Pole for a couple of years. I thought that it would be something
fun for them to talk about at school. At some point I hope that one of them can make
the Q and have a short conversation with someone down there.



73 de NG0R in EN25ue









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MMTTY with Linux

Call me old school if you will but I prefer my RTTY to be FSK hard keyed.



I already had my serial interface setup to allow my Icom 756 to be hard keyed. This
works great with Windows (XP in my case) and MMTTY but I have not been able to find
a Linux program to do the same thing. So far everything that I found has used AFSK
with the audio card and PTT line. Today I was pondering if I could get MMTTY to work
with Linux with Wine. As I searched on the Internet the results did NOT look very
promising. Heck I have only ever setup one other application under Wine and that was
earlier this week and it was a single EXE with no additonal files.



I downloaded the current release of MMTTY which is v1.66G. I already had Wine installed
on my Ubuntu 9.04 pc in my shack. I clicked on the MMTTY installer and it ran and
launched under Wine just fine.



Sure enough I have AFSK with MMTTY using Wine on Linux. But I really want FSK.








There is some magic.  Setup your comm port and then go to the TX port options. 
Set it so that Com-TXD is selected and change the USB port options. (This is not a
USB-->Serial adapter. I have a really 4 port PCI serial card... but the settings
still apply)








Then in the USB port options I tested each of the following options A,B,C,D and with
various levels of success. Ultimately D was the proper setting for me.








I exited MMTTY (to make sure that my settings were saved) and then relaunched it with
successful results. No freezes or delays. It is real time funcitonality and it does
not drawn down the CPU resources on my CPU. A couple of percent CPU is all that I
am seeing from MMTTY running under Wine.



Many people would ask why I really want to use FSK hard keying. I have a very good
350hz CW-RRTY filter in my radio. It is a mechanical filter... no DSP. When I operate
DX or contests I prefer the tight bandwidth that the 350hz filter provides. AFSK is
ok... but the FSK is pretty bullet proof in tough conditions based upon previous operating
experiences. I will see over time how well this works under Linux.



FLDigi is a great program. But sometimes I miss MMTTY for RTTY and now that appears
to be an option with Linux.



73 de NG0R in EN25ue