Roger, I didn't realize that the 1025 (which is what I have) didn't have a preamp on the auxiliary (noise) antenna input!
I chose the 1025 over the 1026 because I did not want the small whip antenna, which only works well if you have RFI close to it. If I would have realized that the 1026 circuit had a preamp, I might have purchased that instead. But when I do use it (very rarely), I almost always use a homebrew W7IUV preamp to feed the noise antenna input, with no issues. What kind of preamp did you add to your 1025? 73, Mike W0BTU On Tue, Mar 17, 2020, 1:18 PM Roger Kennedy <ro...@wessexproductions.co.uk> wrote: > > Having just read some of these posts, I just did a few tests on my > MFJ-1025. > (bought mine second-hand very cheap - a lot of people buy these thinking > they will get rid of any noise!) > > I modified it to become a 1026 . . . you definitely need the extra pre-amp > for the "Noise Antenna", especially on 160m - fortunately they use the same > PCB for both versions, so you can easily add their extra preamp circuit > design on the PCB. > > I normally only use mine on 160m . . . but just did a test on 15m & 10m . . > . it adds no noticeable noise whatsoever ! > > So I think the OP's must be faulty . . perhaps powering it by a noisy PSU? > > Roger G3YRO > > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector