Hi SWR tone ?

Radio is a S6900 with half wave vertical antenna (Venom) . switched the set on other day after not having it on for a few days and  the Hi SWR alarm sounded when keying the mic. Easy fix as it had been blowing a gale outside and one of the sections had slipped right down into the antenna due to a  jubilee clip obviously not secure enough . Tried it today , still windy and wet  keying up on USB  the alarm sounded again as soon as I speak,  checked the swr on FM/AM and it's fine on the same frequency, same power setting .... back on to USB and the alarm sounds as soon as you speak into the mic , took the aerial down and nothings moved because I marked above the joins with a bit of electrical and its fine on FM/AM .
No idea what that would be ?

That is strange for certain, I had something similar on an HF set though, it seemed to right itself again when I used a dummy load offering the set a perfect SWR as though some sort of SWR protection had kicked in and was then reset by using the dummy load.
May be worth a try, I thought the outputs were away as it was only pushing out a fraction of a Watt on low and just under one Watt on high power until transmitting into a dummy load righted it again to my great relief.

Yes It's got me a bit baffled .The  thing that you said that has made me think is when you mentioned reset ? After I sorted the jubilee clip on antenna out and checked everything was OK which it was I transferred another set of.dat  files from the PC . Those files contain other settings as well as frequencies don't they ? I might look into that .
I never got the antenna back up again today as it was blowing and pouring down and is not due to stop until tomorrow night so I'll see what happens.

You say one section had slipped down.
Don't you tape the joints up ?.
Water can get in and end up in the coax.
Did you check the pl259 for water ingress signs.

Yeah  worth mentioning  the joints were all taped except for just above  the one which had slipped I'd obviously removed it to make adjustments a few weeks back and missed that one though there was still some tape below the clip covering the split below the clip so I'd not noticed when it was back up. I'd thought about water getting in as obviously the sections are a little tapered and as it had slipped down there could have been a gap . Hence I've got the thing in the garage to let some air in while this incessant rain stops.
PL259 is all taped where it enters the so239 threads and all , and I tested it with a multi meter for short.   
The thing is everything was taped up and fine yesterday and the readings are what they always were on AM/FM it's just when  I speak into the mic on USB (never tried LSB ) that alarm goes off . I even tried lowering the mic gain but that's what it always was too.

Did it show a short when you tested it.

First and foremost I would test the antenna system with an external SWR meter to ensure that it's not the problem.
When you're satisfied the antenna is okay go into the SWR protection menu on the radio and increase the values or disable it all together. There's no logical reason why mode should make any difference. You could reset the radio to factory settings and then reinstall your current configuration with the programming cable.
It's safe to say if the antenna if fine on an external meter disabling the protection system will not cause you any problems.

73's Gary.

Alan Pilot wrote:

Did it show a short when you tested it.

No it was OK Alan.

O many show a short thought yours would have as well.

I've seen SWR readings do strange things when power is increased if there are things in close proximity to the antenna or if there is something not quite right with the antenna or connections. But if your 6900 is maxed out in export mode then your FM will be putting out more than it can put out on SSB (40W FM as apposed to about 35W peak on SSB), so doesn't look like increase in power related. I'd still check those connections are good though and no wet has got in them like already mentioned by Alan.

GaryWilson wrote:

First and foremost I would test the antenna system with an external SWR meter to ensure that it's not the problem.
When you're satisfied the antenna is okay go into the SWR protection menu on the radio and increase the values or disable it all together. There's no logical reason why mode should make any difference. You could reset the radio to factory settings and then reinstall your current configuration with the programming cable.
It's safe to say if the antenna if fine on an external meter disabling the protection system will not cause you any problems.

73's Gary.

That reset might be worth a try when I get the antenna back up , when the rain finally stops as it seems a strange sort of problem  . I do have a meter  in line which is reading fine AM/FM but the alarm was kicking in before I could see what was happening on there SSB . Never thought to disable the thing at the time .

SangueG wrote:

I've seen SWR readings do strange things when power is increased if there are things in close proximity to the antenna or if there is something not quite right with the antenna or connections. But if your 6900 is maxed out in export mode then your FM will be putting out more than it can put out on SSB (40W FM as apposed to about 35W peak on SSB), so doesn't look like increase in power related. I'd still check those connections are good though and no wet has got in them like already mentioned by Alan.

Yes I fiddled with the power settings and it made no difference I have the antenna down and  in two halves on the stair case indoors so air can get inside just in case any moisture has got in and the pl259 outside has a plastic bag taped round to keep it dry it will probably be the only thing that is dry round struggled to get around today with floods !
Richard.

It finally stopped raining at about 3pm after about 3 days solid so I got the sigma half wave antenna back up , (re taped all the joins this time )  and had a look at the problem with the radio alarm . I'd dismantled the aerial and had it indoors to make sure everything was dry but It was still alarming in SSB as before so before I did any major resets , I tried what was suggested above , I switched the alarm off in the menu and watched the needle on the inline meter instead when I spoke into the mic ,it was only moving the slight amount it was on am/fm . I re-enabled the alarm , and it now seems OK in SSB mode . I hadn't realised you could even disable that feature . Probably a glitch in the software then?

I made a few adjustments before I secured everything again as I'm trying to get the antenna tuned so it's decent on 10m  . I  shortened it a bit at a time , it's still about 1:1 - 1.1.3 up until about 28.5 MHz ( better than it was ) but after about 29.3 MHz or so it's getting  too high . Not sure how well these antennas can be adjusted  to the upper end of the 10m band . or which frequencies in the band are best monitored when the band is open ?

thanks to everyone for the suggestions about the original query .

I slipped some heat shrink over my radial telescopics to stop water ingress. Seems good so far.
My 6900 inbuilt swr says its high, but as I use radial length on a dipole, and cable length, then there shouldn't be high swr.  Do I trust the internal meter, well not really.  Ignorance is bliss.

NoMad wrote:

I slipped some heat shrink over my radial telescopics to stop water ingress. Seems good so far.
My 6900 inbuilt swr says its high, but as I use radial length on a dipole, and cable length, then there shouldn't be high swr.  Do I trust the internal meter, well not really.  Ignorance is bliss.

 I'm thinking along the same lines. the built in swr meter says it's fine ,and agrees with an external meter , but on SSB when I speak it occasionally alarms even with the meter saying it's OK . I thought I'd sused it when I copied the radio settings to the PC and noted that the alarm was set to trigger at swr 1.8 so I upped it to 3 and sent it back . Seemed OK for a while but it still occasionally does it . I decided to just rely on the built in meter or the external one now and switch the damn alarm off .

Talk about a high tone more like a ring clencher..lol
My 69000N does exactly the same thing sometimes.A high tone and It also lowers the output power.I have a K-po power meter/swr inline constantly because we all like too keep an eye on SWR’s and input/output powers.I have a SWR of 1.1 -1.2:1 right through the 11 metre bands and occasionally it still screams out every now and then..It don’t half make me jump at 2am..lol
Now I have a ATU in-line and the SWR is perfect and it still happens.I’ve just learnt to live with it as I know 100% is not a SWR but I still haven’t switched that tone protection off,Call me naive..At least I’m not alone with the blood pressure rising alert and the radio is still working fine.
Cheers Tom.
26 CT 4029

Tom.
I think it's like the sensors and alarms that adorn modern cars which warn us of impending doom . Most of the time it's the sensor that's at fault NOT the part it's supposedly protecting.
Like burglar alarms they false alarm so often people ignore them like the boy crying wolf

So true Rich13,I’ll leave the SWR protection on and just get ready to jump in anticipation.I don’t walk under ladders and all that so I’ll hedge me bets and live with that high pitch tone.
You know what happened to the boy who cried wolf..lol
And no magic blue smoke from my radio as the finals fry.
Cheers Tom.
26 CT 4029

It does stop you dosing off it's one of those unwelcome annoying noises isn't it. 

I think it says in the manual  even if you disable the audible alarm the protection will still cut in at a critical point. It's as if the audible alarm trigger is more sensitive the actual protection set level ? When silenced the power is never cut off and two swr meters are showing less than 1.5 max on mine at all times . Mine only does it on SSB as if it's the varying amplitude of the carrier wave that upsets it?

Rich13,I just think the internal SWR meter is just a guide like most are.I get 1:1 on the external meter and 1:3:1 on the internal 6900n meter while comparing the two on a key.
Anyway sod it..lol
Have a great weekend and DXing.
Tom.26 CT 4029

i might not be swr you get the same noise if not enough power check your psu as if not enough power getting to the radio as you need at least 20+amps

Hi Stephen Gunrunner,I should have also said along with the high tone you get HI S flash on the display,I’ve checked it and it’s definitely a high SWR warning and tone.Even though I’m 1:1 on SWR,As for the PSU I’m using a 50 amp so god knows why it happens occasionally and it also seems to happen to other people and not just me.
Thank for the advice.
Tom. 26 CT 4029

Mine's the same Hi S on the screen.
There's also a setting which gives an alarm if you've been transmitting for more than a selectable set time , but it's never anywhere near the 2 minutes or so mine was set at and as you say the message is Hi S.

I thought it said Hi 5!  Hehe

Seriously though, on my Superstars I just set the SWR alert to it’s lowest sensitivity so at least you get alerted if there is no antenna or a dead short.   Favourite trick for my radio was when using an amp in tow on sideband,  random S HI alarm if you pause speaking for a split second.

Far from the end of the world if you blow the finals on these rigs and you know how to use a soldering iron.   Trannies about £2.50 / pair and tube of CPU paste is all you need.