Hf help

[andrew.shearman]

hi I was on HF last Monday night at 19:30 and last Tuesday night at 19:00. On 20 metters 40 metters and 80 metters I am getting a very lowed nosie can't make out what other ham's are saying this has been gong on for a few weeks now. My HF antenna is a G5 halfwave antenna was on the radio last mondat on 2 metters 144.550 and the guys at my ham radio club told my to clean my HF antenna. I disconnect the antenna. from the ATU and the lowed nosie stop connect it back up and the very lowed nosie started. do u think a new HF antenna would fix this Sharman X-30 Colinear Dual Band Antenna
Gain 4.5dB (2m) 7.2dB (70cm) was told that it wll do 40 metters 20 metters and 80 metters i have an Colinearwoson 2000 2 metter70cm
6 metters antenna would the 2 antennas clash?


Andrew mm3oyl.

[Taf]

There could be a lot of reasons for low level interference, especially if some of the atmospheric ionospheric layers are more active than usual giving you greater range in certain bands. Signal to noise ratios could then be very poor making it difficult to distinguish speech.

Antenna coaxial cabling and plug/sockets could be getting corroded, further reducing S:N. Only a TDR (Time Domain Reflectometer) would truly diagnose that, but a swap out is just as effective if you can get hold of spare cabling and couplers.

Then there's the dreaded "Rusty Bolt" effect... ask at the club about that one.

[Jon T]

Probably a controversial suggestion on this forum, but could this be interference from a homeplug network? Is the interference constant, also does it have a "raspy" noise?

Have you got anything portable that recieves on the HF bands, if you can recieve the noise on that, have a walk up and down your road with you reciever and listen to the change in strength on the interference.

If you do end up suspecting homeplugs then in the first instance have a word with person using them, failing that, report it to OFCOM, they have the power to order the removal of them if they are proven causing interference to users of a radio service.

[bw41101]

Originally Posted by andrew.shearman

hi I was on HF last Monday night at 19:30 and last Tuesday night at 19:00. On 20 metters 40 metters and 80 metters I am getting a very lowed nosie can't make out what other ham's are saying this has been gong on for a few weeks now. My HF antenna is a G5 halfwave antenna was on the radio last mondat on 2 metters 144.550 and the guys at my ham radio club told my to clean my HF antenna. I disconnect the antenna. from the ATU and the lowed nosie stop connect it back up and the very lowed nosie started. do u think a new HF antenna would fix this Sharman X-30 Colinear Dual Band Antenna
Gain 4.5dB (2m) 7.2dB (70cm) was told that it wll do 40 metters 20 metters and 80 metters i have an Colinearwoson 2000 2 metter70cm
6 metters antenna would the 2 antennas clash?


Andrew mm3oyl.

Don't know about cleaning your antenna - would suggest that you clean your glasses or actually put them on before typing OM - LOL.

You haven't stated whether you're using a coaxial or an open feeder for your G5RV, either way would check ALL of your connections, especially the ends where they are attached to the fixings. Dirty connections could also lead to picking up mains borne interference as well. In addition, low receive signal level could be attributed to a wide band carrier signal being locally transmitted - though you would notice a heterodyne (whistle) on the frequency - unlikely across so many different bands.

Another possibility, has a CB'er set up shop near to you? - daft as it sounds this could also be a possibility. I've had issues with interference from same myself - easily cured with the aid of a pair of snips.

73's and Si thee (G6YPU)

[Kymmy]

Reading above all the points are valid.. Only thing I'd like to add is:

Are the Transciever and ATU earthed??