Help - Autotune Failed - Barrett 910

Submitted: Thursday, May 19, 2005 at 11:02
ThreadID: 23120 Views:6641 Replies:14 FollowUps:7
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I've just installed a second hand Barrett 950. The tune test for the autotune antenna returned 'Autotune Failed" on each frequency tried. A friends antenna gave the same results a few weeks ago after he fitted his radio. He is away for 2 weeks so I can't ask how he fixed it.

Does anyone here know anything about this. The cable connections have all been checked, earth strap from antenna base to vehicle body is OK, earth strap from radio body to vehicle body OK, radio does receive/send although reception and tx is poor. Power cable, antenna cable and cable between head unit and radio are not near each other, vehicle battery has sufficient charge. There's not much info in the radio manuals so I hope someone here can point me in the right direction.

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Reply By: Footloose - Thursday, May 19, 2005 at 11:10

Thursday, May 19, 2005 at 11:10
Tony. I'm more familiar with the Codan stuff, but here goes. There are 2 main sources of problems with this kind of aerial, earthing and RF power. (lack thereof). Check your aerial cable to see if there's a short. More than likely you have a poor earth connection somewhere. Make sure all aerial earth points are clean and making good contact. Don't rely on the thing just being there.
You can check to see if its the aerial by listening on the auto to a shortwave broadcast station. Then pull the coax out and plug a long piece of wire in instead. If its louder with the wire its definately the aerial.
Hope this helps.
AnswerID: 111915

Reply By: Member - Banjo (SA) - Thursday, May 19, 2005 at 11:17

Thursday, May 19, 2005 at 11:17
Had the same on mine a year or so back - had to send it back to the factory for some warranty work. They are very (very) complex inside - lots of widgets in there - they are a very reliable item of technology but on occasions issues can develop of course. Mine had moisture inside - this can be an issue with the earlier cases - the new blue cases are heavier/stronger - they old ones can get a hairline crack at the top (as the antenna drags under trees etc) and temperature changes can suck the moisture in. Your symptoms were exactly what I had - poor TX and RX - failing to tune properly. Anthony Benbow at the factory in WA is right up on it - he fixed mine in a trice - being a second owner you may be out of warranty - even so, it might not costs heaps - whatever the cause, a module or two soldered in might fix it - freight via Aust Post is cost efficient for this size of pacel - as you say, it would be good to test the radio with another antenna, to make sure that the 910 is the snag.
AnswerID: 111916

Reply By: Voxson (Adelaide) - Thursday, May 19, 2005 at 13:46

Thursday, May 19, 2005 at 13:46
My brand new one did the same and it was not easily repairable...
If you have all the connections right then you are most probably stuffed....
AnswerID: 111930

Reply By: floyd - Thursday, May 19, 2005 at 18:46

Thursday, May 19, 2005 at 18:46
Sounds like an antenna failure or problem with the radio unit. It is unlikely a problem with leads, cables or power.
AnswerID: 111958

Reply By: Peter 2 - Thursday, May 19, 2005 at 18:51

Thursday, May 19, 2005 at 18:51
Having installed dozens of them I suspect that it may be an antenna problem. If it were an earthing problem it would probably only play up on a few freqs.
Mind you I would be checking that everything is earthed correctly especially the bullbar or whatever you have it mounted on is earthed to the chassis. Physically remove a couple of bolts from the mounts, file to shiny metal and re-install.
It is really surprising how many bars etc are not earthed!!
AnswerID: 111960

Follow Up By: Mike Harding - Thursday, May 19, 2005 at 19:42

Thursday, May 19, 2005 at 19:42
>If it were an earthing problem it would probably only play up
>on a few freqs.

Why do you think that? I cannot think of a technical reason why a bad earth at the antenna would not affect the whole HF frequency spectrum although possibly more so at the low frequencies than the high ones - but VKS737 doesn't go too high anyway.

I do wonder if these complicated auto tune antennas are worth the cost and trouble. It's possible to buy a jumpered antenna which covers the whole VKS737 area for ~$150.

Mike Harding
FollowupID: 368324

Follow Up By: Peter 2 - Thursday, May 19, 2005 at 20:20

Thursday, May 19, 2005 at 20:20
Mike I was trying to keep it simple for the non tech types ;-))
what you say is true but in my experience with installing and repairing vehicle HF installations (I've seen some beauties believe me) is that they will quite often tune some freqs but fail on others, probably due to the resistance changes of the earth (or lack thereof). Some as you say work ok top end others bottom end, I've even had a few that refuse to tune one frequency but work fine on all the others.
I've got a first generation Barrett antenna (was single stud and changed to a four point mount under wty) which has worked flawlessly since purchase in the early 90's. It has been on the truck continuously all its life and is on constantly, I'd never go back to a tapped whip.
FollowupID: 368334

Reply By: Member- Rox (WA) - Thursday, May 19, 2005 at 22:06

Thursday, May 19, 2005 at 22:06
Mine started out ok but developed auto tune fail. The cause My poor instlation, the cable wore through the insulation causing a short between the coaxil & 1 of the other 4 wires. I stuck elec tape to it then got plug from Barret & shortened the cable. I say you definitly have a short. Do you have an extention cable? if you can remove it just temp & plug the short cable into the box try again. Also ALL joins need to be soldered to get the best contact.

If all else fails Ring barrets in WA.
AnswerID: 111996

Reply By: age - Friday, May 20, 2005 at 08:07

Friday, May 20, 2005 at 08:07
We use to get a similar problem with the Codan auto tune in our work trucks. After looking for the obvious shorts etc as mentioned above we used to do a complete power down, go outside and lightly tap the the aerial as the tuning slug that winds up the core used to get stuck. Go back into vehicle power up again and pick the lowest frequency and get aerial to tune to it. Then pick a high frequency and tune to it. Wrks the slug up and down the winding - may work in this case if not an electrical fault - Cheers
AnswerID: 112032

Follow Up By: Member - Banjo (SA) - Friday, May 20, 2005 at 08:25

Friday, May 20, 2005 at 08:25
No slug in the Barrett - all done with relays bringing coils in and out of the wire length equation - no "moving parts" as found in the Codan. Not saying its better - just different.
FollowupID: 368380

Reply By: Peter - Friday, May 20, 2005 at 11:49

Friday, May 20, 2005 at 11:49
Also check the radio is set to use the autotune antenna rather than other types of aerials.
AnswerID: 112064

Reply By: Tony J - Friday, May 20, 2005 at 15:48

Friday, May 20, 2005 at 15:48
Thanks all for your input. Tried everything without any luck. Am now in email contact with Barrett and they are trying to help. Looks like a trip to one of their agents to get it fixed. Antenna is only 2yrs & 3 mnths old. Am heading to CSR next month so a quick repair is vital.
Thanks again,
Tony J
AnswerID: 112094

Follow Up By: Member - Banjo (SA) - Saturday, May 21, 2005 at 09:44

Saturday, May 21, 2005 at 09:44
You may lose your 'vital' time with the agent (seeing you are in a hurry) - I took mine to a a genuine radio expert (agent) but the analysis of the problem still ended up at the factory (the time issue didn't matter to me then) - my moisture issue had done little damage as it turned out - a couple of components on a circuit board had to be replaced - (as said, there is a long skinny circuit board with heaps of gizmos on it, running right up the centre of the autotune - in my view, only a factory technician is going to find which ones are dud) - and they replaced a few other small bits and pieces while in there. As mentioned mine was warranty (under 3 years) - but subsequent owners may not be offered that past 12 months - the repair was going to come to about $130 I think, plus postage (its mainly labour - analysis, plus the work). BOL.
FollowupID: 368531

Follow Up By: Tony J - Saturday, May 21, 2005 at 19:56

Saturday, May 21, 2005 at 19:56
Thanks Banjo, had a thought it might go from an agent to the factory so I've now found a way to get it to Perth overnight from north coast NSW, at a cost, but, what price can you place on safety with this trip! I have had a good response from the Barrett service department, absolutely brilliant in fact! I tried everything Barrett suggested too, but it seems like something inside it has gone astray. Anyway, it will be in Perth on Tuesday.

Thanks again
Tony J
FollowupID: 368555

Follow Up By: Member - Banjo (SA) - Saturday, May 21, 2005 at 22:23

Saturday, May 21, 2005 at 22:23
Indeed re Barrett backup - I could not have asked for better service and in this day and age, it needs to be acknowledged. Cheers.
FollowupID: 368567

Reply By: angler - Friday, May 20, 2005 at 21:17

Friday, May 20, 2005 at 21:17
Had a similar problem with my Codan after some years of use. It turned out to be a short in the RG58 cable. Once I confirmed the short I started cutting back the cable till I found it. The inner was kinked and held in place by the dialectric. Years of use suddenly caused a short between the outer and inner conductors.

All electric problems are simple shorts or opens or somewhere in between, once you do all the hard parts it's easy.
AnswerID: 112133

Reply By: Rob - Sunday, May 22, 2005 at 13:53

Sunday, May 22, 2005 at 13:53
Try checking the options on the menu. The Radio Unit must be correctly configured to work with the Autotune antenna.

If the radio unit thinks there is something other than an autotune connected (e.g. a seperate RF power-amplifier) then you will get auto-tune failure each time.

Sorry - I cannot remember the correct sequence - something like "options" or "accessories" in one of the LCD menu items.

I discovered this while playing with the radio trying to find hidden menu options and thought I had stuffed the unit. Fortunately I retraced my steps and got the radio to recognise the antenna once again.

Hope this may be of use...

AnswerID: 112290

Reply By: Member - Landie - Monday, May 23, 2005 at 16:11

Monday, May 23, 2005 at 16:11
Hi Tony

I had a similar problem with a brand new antenna that I had professionally installed a couple of years ago. We checked absolutely everything, connections, the works and to no avail.

We then exhanged the antenna for another new one with a similar batch number and had the same problem. Finally we changed it for another with a a completely different batch number. I have not had a problem since.

The auto-tune failed (on the original) after a short period of time and appeared to be a heat problem. We pointed this out to the factory at the time and sent the original unit back to them. I suspect there was a component that was possibly faulty in a particular batch series that was sensitve to overheating.

I posted a report at the time, however I cannot locate it as it was some time ago.
AnswerID: 112438

Reply By: Member - Landie - Monday, May 23, 2005 at 20:46

Monday, May 23, 2005 at 20:46
As a follow up to my previous post. The serial number of my original 910 antenna was S/N 5632. The second one we tested was within 100 of this number and it failed also. The systgem was purchased in February 2003.

The one I now have (without one problem) is now-where near these serial numbers.

Check your serial numbers if you have had a problem.....

AnswerID: 112491

Reply By: Skinny- Wednesday, May 25, 2005 at 16:04

Wednesday, May 25, 2005 at 16:04
Hi Tony, are you there. Can you hearme. Have you got your HF fixed and have you left on holidays yet. What was the problem?

AnswerID: 112815

Follow Up By: Tony J - Thursday, May 26, 2005 at 18:18

Thursday, May 26, 2005 at 18:18
Problem turned out to be a fualty wire in the antenna tail. Cable has 4 control wires plus the coax. One of the control wires had a break that stopped the antenna tuning. Cable must have been stretched at some time.
Tony J
FollowupID: 369211

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