Cheap QRM Eliminator

Have just bought a cheap QRM eliminator in the hope of clearing some of my S7 of noise, it should be here in a couple of days. I figured it would be worth a punt at £45 delivered, will report back when it arrives.

I'll keep my fingers crossed for you Mark!  
I tried just about everything to get rid of the S7-S9 I was getting including getting a second 1/2 wave silver rod and mounting it on a pole as far away from houses as I could with my SS6900N. Although I didn't purchase a QRM eliminator but went to the next step by getting a HF radio, and that did it for me and only a few hundred quid lighter in the bank.

Good luck with the licence.

Tony

The eliminator arrived yesterday and am very impressed, noise levels are down to S3-S4. The only problem I have is how to attach the PTT to my SS9900, for now have ordered a push to make switch that I will have to activate each time I key the mic,

Does anyone know how I can make a permanent solution for the PTT?

Am quite proud of myself, I have a Zetagi pre amp and was able to work out which was the ground going to the relay. Have temporarily soldered the ground wire from the eliminator to check it is working.
Now I need to drill a hole in the pre amps case and secure the wire, then the job is a good un.

Good result Mark, I have never tried a pre-amp as I read in loads of places that it will bring in more noise as well as wanted signals.
I hope you can now enjoy the radio and get lots of copies (QSO's)

Tony

Well, I now know why it was so cheap. Fired up transmit on USB and my SWR warning came on, the eliminator is now stuck in transmit mode. It's supposed to be rated for 100W yet keeled over with about half that. I guess I'll be saving up for a Wimo one, it's a £160, so I hope it will last better than the cheapo Chinese one.

I wound a choke out of my coax and that has helped a little, but am still around six pound of noise on FM without the eliminator.

What is it like without the preamp.

The pre amp is variable from -10 to +30, I have it set on 0, so no gain.

I was getting s7 of noise and worked out it was the downstairs tv! Turn it off and it’s fine ‍�

13oots2 wrote:

I wound a choke out of my coax and that has helped a little, but am still around six pound of noise on FM without the eliminator.

That suggests the cause of your noise is common mode RFI which is usually caused by a lack of a decent RF ground so the antenna system uses the coax. A RF choke at the antenna end of the coax may reduce it significantly.

Northern Crusader wrote:

13oots2 wrote:

I wound a choke out of my coax and that has helped a little, but am still around six pound of noise on FM without the eliminator.

That suggests the cause of your noise is common mode RFI which is usually caused by a lack of a decent RF ground so the antenna system uses the coax. A RF choke at the antenna end of the coax may reduce it significantly.

The choke is wound about 3 inches from the antenna, even with my noise levels am getting the Italians coming in well and a chap from Romania on a couple of days. Have still to make a contact with anyone, but am sure I will get there in the end.

Have been eying up the MFJ-1026 rather than the Wimo, it costs a lot more and seems far more versatile, it is possible I could afford it this side of Chrimbo.

Have an xphase QRM elimination I like you have no separate PTT control but added a switch into the microphone on my SS9900 M9 mic, when you press the PTT it goes to earth thus cutting out the RX circuit on the eliminator, it works but still have QRM issues here. I have a new  to me second hand antenna ready waiting to be  replace my Serio Venom 1/2 wave this I am hoping will help being able to beam the Maco 2 element delta loop away from the source.

Have just ordered a cheap car battery and charger, I don't think that any of my electrical goods are causing the QRM, you never really know until you test it.

Turns out my QRM eliminator is working, it is just the TX LED that is stuck on, I also had a dodgy patch lead that was giving the high SWR. I decided not to go with anew expensive QRM eliminator, as most seem to have pretty much the same innards as the much cheaper Chinese ones. As a back-up I have bought one directly from China that has a built in PTT circuit, £43 delivered which isn't too bad, it should arrive around new year.