Well, some improvements today after encouraging words from forum members. Much opening and closing PX3 case pressing PCBs, reseating connections and cables, moving power leads and suddenly things are 20 dB better. I can now hear the weak beacons with the PX3 switched on. Now to tidy up and try and get a configuration of equipment so that I can test a little better.
That was a close call, I was in the local emporium today and if there had been a certain radio in stock I may well have bought it today! Thank you all again. My confidence is much restored. 73 David Anderson GM4JJJ > On 28 May 2015, at 18:08, <ejk...@gmail.com> <ejk...@gmail.com> wrote: > > David, > I also do some 2 meter weak signal, been doing it for many years. I also > have the KX3, PX3 but I use the KX3 internal 2 meter module. I have other 2 > meter SSB rigs but find the KX3 to be very good on 2 meters. Your email made > me curious and I did find the signal near 144.4 but I could not find any > other signals being picked up from the PX3. I use the cables that come with > the PX3 and my PX3 is mounted above the KX3. I also have an external DEMI > 222/28 transverter connected to my KX3, again with great results and no > signals picked up from the PX3. Using the PX3 on these bands is great, I can > cover a large area of the bands and monitor everything I want. > Hope it works out for you, good luck, let us know how it works out. 73 > Emory WM3M > > -----Original Message----- From: David Anderson > Sent: Wednesday, May 27, 2015 1:26 PM > To: Elecraft Mailer > Subject: [Elecraft] KX3 and PX3 with 2m Transverter comments > > I bought a KX3 and PX3 with a view towards using them with an external high > performance transverter for 144MHz (with an IF of 14MHz). My main interest > being weak signal operation on VHF. The ability to use the I/Q outputs with a > sound card or PX3 and the excellent receiver performance in reviews seemed to > indicate this would meet my needs. > > Unfortunately it looks like this is not going to work out for me, as the > level of radiated noise at VHF from both the PX3 severely masks weak signals, > there is also a huge radiated birdie from the KX3 near 144.4MHz. > > Turning on the PX3 and listening on 144MHz gives bands of noise every few > kHz which mask weak signals in the noise and I can liken it to listening to > the 6m band with a Band 1 TV transmitter putting out video sidebands over the > band. > > Without the PX3 switched on I can hear distant beacons in the noise, but they > are buried by the PX3 when it is switched on and plugged in to the KX3. The > antenna is 60 feet away from the rigs and is fed by Heliax. Have tried > separate supplies for transverter and PX3, running from batteries on KX3, > nothing seems to reduce the QRM from the PX3 to an acceptable level. > > There also is a huge S9 spurious near 144.4 from the KX3 that is independent > of band/freq/mode. Confirmed by listening on another receiver in the shack. > > It is so hugely disappointing, I had looked forward to this day, having > finally got my rotator and antenna back up on the tower I am faced with > looking for another rig to drive the 2m transverter. Unfortunately I don't > think it will be Elecraft. Perhaps Elad might be an alternative, but I need > to consult the weak signal VHF community first. I will keep the KX3 and PX3 > for QRP HF work most likely as selling it at a loss would be a bitter > alternative. > > On HF where the band noise and signal strengths are much higher I don't find > the same problems, though there are still spurious signals shown on the PX3 > there. I could live with them I think, but on what is a nice quiet 144MHz > band here, the racket from the PX3 is impossible to put up with. > > Incidentally I wonder what causes that big birdie near 144.4 from the KX3, > and if is it related to the similar one reported on the K3? There doesn't > seem to be a lot of commonality between the designs. > > Sorry if this sounds like I am trolling, I am not, I love the Elecraft ethos > and products, it is just they don't appear to work for my specific needs. > Unfortunately it wasn't possible to try before you buy here and I ended up > being the guinea pig. > > 73 > > David Anderson GM4JJJ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to ejk...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
