[CQ-Contest] SSB & CW On Same Band

[donovanf at starpower.net]

Hi Tom, 


The W3AO Field Day team has used multiple transmitters in the 
same band for more then 20 years with no trace of interference at all. 
We often have four transmitters on the same band (CW, SSB, digital 
and GOTA). 


We do not use any fancy filtering. The key to our success is using 
horizontally polarized antennas installed end-to-end. For example, 
on 20 meters we use four Yagis installed in a straight line with 
nearly 300 feet of spacing between the tips each Yagi. 


The same principle is applied with dipoles. on 80 meters we use 
three dipoles installed in a straight line with about 300 feet of 
spacing between the tips of each dipole. 


Its important to use transmitters with clean phase noise characteristics. 
Some of the early synthesized transceivers are unusable such as the 
Kenwood TS-450S. Many other common transceivers such as the 
FT-1000MP, FTdx5000 and K3 are completely interference free. 


Some of the serious DX contesters also have the capability to 
operate in band with 1500 watts. A clean transceiver, a very clean 
amplifier (very low IMD), and widely spaced antennas with proper 
antenna orientation are keys to success. 


Of course DXpeditions have also successfully conquered these same 
issues for years. 


73 
Frank 
W3LPL 






----- Original Message -----

From: "Tom Hellem" <tom.hellem at gmail.com> 
To: CQ-Contest at contesting.com 
Sent: Saturday, March 18, 2017 1:54:50 AM 
Subject: [CQ-Contest] SSB & CW On Same Band 

Has anyone successfully run 2 stations on same band, SSB &CW, 
without interference between the two? For example, FD or IARU. 

We have tried it several times and have always ended up with moderate 
to severe interference to the point that one station had to qsy to 
another band. 

Obviously (I think) the filters that are in common use like Dune Star, ICE, 
NQN, etc. don't work because they are band pass filters. But has 
anyone designed/built a filter with sharp enough roll-off to make this work? 
Or, would a pair of K-3's , etc. fit the bill? 

Would love to hear from people that have made this work for them, and how 
they did it. 


73 

Tom 
K0SN 
_______________________________________________ 
CQ-Contest mailing list 
CQ-Contest at contesting.com 
http://lists.contesting.com/mailman/listinfo/cq-contest