Message	Date	From	Subject
8757	2013-06-25 20:13:48	n5emqrp	Field Day Filters
Group, I'm just back from FD and like many others have dealt with station overload from close together transmitters. Dealing with adjacent bands is not bad - lots of solutions. I would like to hear how others deal with simultaneous SSB and CW positions in the same band, too. However, my question is this . . . Has anyone tried to operate two transmitters on the same band segment - CW and PSK (specifically, 20M CW and PSK at about 14.070). The KX3 does a really good job of trying to deal with it - I'm sure other radios with about 90+ dB of dynamic range do, too. Has anybody really tried to design a filter to deal with this - or do you just time share between the two modes? It would be a really large thing (or a very lossy one). I don't have power to deal with, 100% QRP at 5W. Still, I'd like most of that to reach the antenna. On to the simulation software . . . Ed, N5EM (FD with the W5MSQ, Houston QRP Club).
8764	2013-06-27 10:20:05	KK7B	Re: Field Day Filters
Hi Ed, I've done both a high Q receive antenna coupler and front-end crystal filters to address that problem. Here's a link to slides for a talk I presented at FDIM in Dayton this year with photos of both those approaches for 40m. No design details available--I used parts

Group,

I'm just back from FD and like many others have dealt with station overload from close together transmitters. Dealing with adjacent bands is not bad - lots of solutions. I would like to hear how others deal with simultaneous SSB and CW positions in the same band, too.

However, my question is this . . . Has anyone tried to operate two transmitters on the same band segment - CW and PSK (specifically, 20M CW and PSK at about 14.070). The KX3 does a really good job of trying to deal with it - I'm sure other radios with about 90+ dB of dynamic range do, too.

Has anybody really tried to design a filter to deal with this - or do you just time share between the two modes? It would be a really large thing (or a very lossy one). I don't have power to deal with, 100% QRP at 5W. Still, I'd like most of that to reach the antenna.

On to the simulation software . . .

Ed, N5EM (FD with the W5MSQ, Houston QRP Club).