Interference on signal

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matth2004
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Interference on signal

Post by matth2004 »

Have setup a new Diamond X-50 antenna on top of the roof and run some LMR195 to it (approx 20m of cable) but I am getting interference every so often and can't quite figure out what it is. When listening to VK6RAP and VK6RTH on 2m it seems to chop in and out. Sample audio of this mornings broadcast from 0900 is below. You'll hear interference momentarily when I start recording and around the 1 minute mark as well.

https://soundcloud.com/matt-483/voice00001-20150315

Have turned off all power at the meter box to make sure that isn't causing the interference. I've spoken to a few gents on VK6RTH and they say that I boom through quite clearly to them so I'm guessing it's just an RX issue. Haven't had a chance to try out another radio. Haven't had a chance to talk to anyone on 70cm to see if it's the band. Listening on CB banter on 1, 3, 4, 5 and 8 I don't seem to get the interference. Haven't heard any interference on VK6UU's repeater VK6RLM however I haven't spoken to anyone for longer than say 30 seconds on it so I could have been hitting a clear patch. Any ideas as to what it might be?
Matt
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Re: Interference on signal

Post by robbage »

Listen to the news on 70cm tonight. Are you using the X-50 to listen to CB or a different antenna? Do you have solar PV and if so, did you isolate that as well?
FWIW I can't use HF or 6M due to noise from neighbours solar although it doesn't seem to affect VHF or UHF significantly. We also got PV recently which doesn't affect VHF but who knows with so many different brands of converters.
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matth2004
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Re: Interference on signal

Post by matth2004 »

Roger, if I'm about I'll listen to the news. Yes using the X-50 to listen to CB as well. Don't have any PV installed here and from a quick glance none of our immediate neighbors do either.
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Re: Interference on signal

Post by matth2004 »

Further to that listening to VK6RLM 146.750 at the moment for a solid 5 minutes with chatter I cannot pickup any interference. VK6RTH and VK6RAP on 2m still getting interference.

Very odd....
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Re: Interference on signal

Post by matth2004 »

Absolutely crystal clear for the WIA news tonight on VK6RUF on 70cm.
VK6RAP still the same issues on 2m :(
VK6RLM crystal clear on 2m
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Re: Interference on signal

Post by matth2004 »

An update:

- Popped an antenna on a handheld and stuck it on 146.700 listening to the news. Really quite bad interference and next to no reception using an antenna in or just outside of the house compared to the antenna on the roof. Walked out the front and down the street about 20 metres and voila 146.700 was as crystal clear as 439.800 for the news. Odd I thought.
- Walk back towards home and the issue begins to pickup.
- Tried another handheld tonight and while the second handheld does not pickup the news as clearly on 2m as it does 70cm, it definitely does not have bursts of interference like you can hear in my soundcloud link earlier.
- Tried different batteries in the handhelds but it seems to be the transceiver itself.

As such I've ruled it down to a radio fault. 2m probably isn't as clear here as 70cm is because of the propagation characteristics and environment in this area. But it seems that the other radio is super susceptible to whatever spurious emissions or otherwise are coming through on 146.700.
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Re: Interference on signal

Post by VK6ZMS »

Have you checked the SWR ?
It sounds like you have a poor connection, possibly a PL259 thats not terminated properly or a sus antenna.

Also VK6RUF is no longer licensed and VK6RLM is WARG's repeater.

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