Heartbeat

[VK4OI]

I have just setup my remoter on a 7100 some 300km away from my home site. At the remote site I had both units working fine. I have bought the control and head back with me to the home site and have got it working all ok except for this issue. My remote site is on a 3G connection and works surprisingly well on audio both ways. The issue is I seem to be getting a heartbeat about once every 2 seconds or so, On FM it does not break the mute but I see the S meter bounce up but can not detect any noise or sound on incoming audio or my tx audio. On HF though this heartbeat gives a S9 hit on HF and it obviously effects the receive signal. Has anyone else found this. It worked when both units were at the same site perfectly and no heartbeat but now when live via the internet and 3G I have this heartbeat issue. Any advice would be appreciated

Mark

VK4OI

[vk3bia]

Mark,

Somebody turned on a high power electric fence at or in the area of the location?

I have had some experience with several 3G HSPDA routers not with remote rig but running voip lines and no issue, only problem I had was the IP was behind a nat and the modems remain connected  but the data stream seems to die, maybe in 20 minutes or 10 days. Normally a reconnect resolves it. Speed wise I found it very good, just unreliable. Your carrier would most likely be a different setup to mine however.

I had the 3g on a 1mtr dish (1.9ghz HSPA) beside the vertical antennae for 2 and 70 at the 80ft level and never noticed any interference. However I only run FM on the radio with remote rig to a local building by wlan.

Harry

[pd0swl]

An electric cattle fence nearby?
They can cause strong pulses from LW to VHF.

The IC7100 AGC is extremely sensitive to such spikes.
I always leave the NB switched on at a low level.

Most electric fence problems are caused by sparking of bad connections or (wet) vegetation shorting to ground.

73
Paul
PD0PSB

[VK4OI]

I don't have my elec fence turned on at all...its funny this morning the heartbeat isn't there....maybe a neighbour has a fence. I will have to find out if that is the issue. My elec fence doesn't cause any issue

[VK4OI]

This is weird

On FM I see the S meter bounce but it doesn't open the mute and when someone is talking on FM there is no hint of disturbed audio. On HF the heart beat seems to come and go sometimes its there other times not but when it is there then it does hit the received audio but on FM you see that S meter bouncing up to 10 over 9 every 1 to 2 seconds

[pd0swl]

FM is almost immune to pulse interference.
That's a reason why the mode was widely adopted after the AM era.

Switch to AM on the same frequency,turn the NB off,and you will hear the pulse.

I occasionaly have a fence here, ranging far into VHF on rainy days.

73
Paul
PD0PSB

[VK4OI]

Ok the issue is now known. I have cattle agisted on my farm but due to the drought they had been taken off to a state forest lease that still had some grass. Since it has rained over the last 5 weeks the farm has come alive again the grass you can almost see it growing and is over 500mm high. The people rang me last week about putting the cattle back onto the farm. I thought they said it would be this friday coming as I set the remoterig up last friday night here. They rang today to let me know they have got cattle back on there  which they did last saturday so that explains why on friday night when I got it working it was great but the next day I was getting this heartbeat....because they turned my elec fence on...So now the next job is to get my home automation system I have up there which I can control the power to the 7100 and also the RRC radio end also some other gear I will make a unit that when I want to play HF from here at home I can turn the elec fence off then turn it back on when I am finished

Mark
VK4OI

[vk3bia]

Mark,

you might be able to minimalise the problem a bit. Switching it off while using the rig is good as long as the cows don't realise its off, cause then they will walk through it.
My approach would be as if there was a fence fault pulling the voltage down, isolate section by section and see if the problem is just one line.  Then if its not obvious like a blade of grass shorting it do the legwork at night and see if these a a crackle and blue spark on an insulator along the line.

best of luck reducing it.

[pd0swl]

Mark,

When the fence is off and the 7100 is on, just place a waterproof speaker on the field connected to your rig.

You can directly talk to the cattle and they'll stay around listening to your QSOs ;-)

73
Paul
PD0PSB

[Jan (Microbit)]

Mark,

When the fence is off and the 7100 is on, just place a waterproof speaker on the field connected to your rig.

You can directly talk to the cattle and they'll stay around listening to your QSOs ;-)

73
Paul
PD0PSB

ROFL! 

[VK4OI]

This lot of cattle are younger ones I am told. Usually we leave the fence wire down across the driveway to the shed and hangar the cattle will actually stop and won't cross it even though it is sitting on the ground. Once they have had a couple of zaps thy know what that red and white twisted wire does. The more  I use it now then more I am convinced the switched powering the CAI networks board is the source of the "noise" I am getting there other than the fence of course. The fence isn't shorting anywhere that I know of as we keep the grass under the wire always cut so it doesn't touch. I will be back up there at the end of this month so I will attend to looking if the insulators are breaking down at all and fix that switchmode.
I have to say I am so impressed how well the Remoterig works with the 7100 and the AH4 tuner it is just so easy especially since my 3G connection can get pretty slow at times up there. There are so many people in the bush around the mountain the cell site is on using mobile broadband it isn't funny. I use a VPN to log in now to the CAI unit and the RRC. It just all works so well I certainly would recommend the remoterig system to anyone.

Mark

VK4OI