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KX3 upgrade during W6 visit (a roofing filter question)

Hi OMs,

I am going on a W6 trip in two weeks and I plan to take my KX3 with me. Apart from having conflicting reports on whether I need to power the KX3 on at the airport check or not (read take the AA batteries) I now have a huge dilema about the roofing filter upgrade. I do not have one and I am not sure if I really need one.

All the post forums say that it will protect you from strong close signals like in a contest but is there a benefit for SOTA operations? The general answer is no, because we are using simple antennas. BUT…

… how about 40M? It is crowded 24/7, would it help?
… how about local QRM from commercial equipment on hilltops?

Is there anyone who did the upgrade?

I am already about to buy the internal tuner so I am considering if another investment is worth.

73 Marek

1# Even in crowded bands there is enough selectivity (SSB), the main benefit would be realized in CW upon which it would be worth the cost benefit for improved performance.
2# The filter you are referring to will do nothing for that type of QRM. The way the KX3 selects the hardware filters is entirely based on whether or not you can use it at a particular instance. e.g with a 2.8 Khz roofer width this won’t come into action.

The price is criminal for what it is. Wouldn’t purchase the radio again. Its a nice toy, I would not compare it to a Racal, or my PicAstar.


But carrying an RA17 or RA117 or even RA1772 up a summit is just a bit harder than carrying a KX3!

It’s not that the reports are conflicting, the people doing the screening are not consistent. Do what your airline tells you to do regards batteries and electronics. I always can demo that my 817 works as a receiver but have never been asked to demo it.

Don’t tempt me Andy, speaking of which - are we having another one ? :wink:


I also have the KX3 with tuner and roofing filter. First : I have taken my KX3 with me four times overseas and never had to turn it on or even take it out of the bag. My first trip in 2013, I took it to Kauai with internal batteries but didn’t need it. I now keep the batteries out because I use an external LifePo battery. A trip to Portugal was the same and to Canada. Never had to take it out of my backpack. This year I am going to Ireland. I pack the antenna in my suitcase.
I find the filter most useful for me in crowded bands and in big pileups. I operate mostly CW.
Where in CA will you be traveling? I am down near Santa Monica, Los Angeles area.
Don, NK6A

I am (still/not yet) capable of CW, therefore SSB is my main interest. To be completely honest, I tried narrow SSB filters on FT-1000 Mark V as well as on IC-756 Pro II and it never improved listening experience. It is usefull on RTTY though so I expect it to be nice for CW as you said. So I am probably skipping this…

I will stay at Laguna Beach. I am visiting my relatives, so I am not sure if there will be any oportunity for a SOTA activation. :frowning:

Where in W6? Only on mountains or also in cities?

I have a KX3 without roofing filters. I have not missed them. I operate SOTA or in Palo Alto with a fan dipole. In town, local RFI is the limiting factor.

If you are getting interference from high power transmitters on hilltops, use RF SHIFT to reduce it. The roofing filters will not help that.

I have not had to turn on my KX3 at airport screening, but I do keep Eneloop XX batteries in it all the time.


I will stay at Laguna Beach. I am visiting my relatives, so I am not sure if there will be any oportunity for a SOTA activation. :frowning:

You don’t need the roofing filter. And if you need to use RX IF Shift to minimize images, the roofing filter is disabled anyway.

73, Barry N1EU