Narco A150 test / repair

Gavin Bell · Post by **Gavin Bell** » Sun Sep 19, 2010 8:43 pm

Hi,

Can anyone suggest where I can get a Narco 150 transponder tested. Have refitted to a/c and no sign of life. Have checked wiring into the cradle and all seems to be okay.

Also have an altitude encoder to fit once sorted. Do these units normally require calibration, the destructions give a very longwinded way of setitng up with specialist equipment. I was thinking of getting airborne then doing a cross check with a LARS.

Thanks

Gavin

Kevin Stewart · Post by **Kevin Stewart** » Sat Oct 02, 2010 10:16 pm

Hi,

I've only ever posted Narco kit back to the USA for repair. There is always the risk of being charged VAT & duty again on the unit which I have had happen.

I have had trouble with Narco gear not seating properly in the cradle. Are you sure it is engaged properly?

Are you sure that it is totally dead? If you put an ammeter in series with the transponder fuse and turn it on do you see any current flow? If not and you are happy that the connections are all correct then I would take a look inside the unit and check for obvious problems like bad joints, loose connections, internal fuses, etc.

Hope this helps.

Gavin Bell · Post by **Gavin Bell** » Sat Oct 02, 2010 10:41 pm

Hi Kevin,

Found the power issue with the unit and have refitted to the aircraft.
Have made 2 flights since and have had negative ID from LARS, so am going to have to investigate the aerial connection.............

Was working prior to removal, so am hoping it is something to do with the current installation rather than the unit?

Ideally would like to find somone with the same unit and pop it into their aircraft to test. Any takers?

Cheers

gavin

Kevin Stewart · Post by **Kevin Stewart** » Mon Oct 04, 2010 9:46 pm

The tray in our old aircraft became slightly twisted and the aerial connection was not making contact. I would suggest making some measurements with a ruler to work out how far in the unit needs to be to make contact.

Gavin Bell · Post by **Gavin Bell** » Tue Oct 05, 2010 9:42 pm

Hi Kevin,

I did just this on Sunday. The connection for the aerial within th eunit is soldered into a bracket. That solder had broken and the internal aerial tube was being pushed backwards, so no connection. Connection now fixed, so just awaiting flight test. At least I have found a definite problem, so hope it cures it. Next step is to interface the altitude encodera

Cheers

Gavin

Gavin Bell · Post by **Gavin Bell** » Sun Oct 10, 2010 8:16 pm

Transponder tested today and negative Squawk - the parrot is lying feet up on the floor of it's cage!

The green light used for ident is permanently lit, not sure if this is normal.

Might try to find a repair shop in the states unless anyone knows of a good local repair shop?

Gavin

Kevin Stewart · Post by **Kevin Stewart** » Sun Oct 10, 2010 9:03 pm

That's a bugger then! I see the last one for sale on afors was back in January. There a number on ebay.com but they are all in the USA so you will have VAT & duty to pay when you import them. Do you know someone in the USA who could bring one over at Christmas?

Gavin Bell · Post by **Gavin Bell** » Sun Oct 10, 2010 11:04 pm

Hi Kevin,

The prices of them new in the USA makes the 2nd hand choice a poor one. Narco solid state direct replacement for about £1,100
Not in a mad panic, it won't increase my cruise speed or help my landings

Gavin

Brian Hope · Post by **Brian Hope** » Mon Oct 11, 2010 8:26 pm

Heard about this today if you're interested.

Narco AT155 A/C with mount. Offers around 600 pounds. 07870 570774

Gavin Bell · Post by **Gavin Bell** » Tue Oct 12, 2010 9:52 pm

Hi Brian,

AFter exhaustive searches, £600 is about right for a used transponder. From the states they are about the same bench tested with a limited warranty. I'm thinking at £1100 to bring a new Narco in from the states with a full warranty and solid state technology (no tube) then that is a better investment. It costs in the region of $850 to have the tube replaced.....

Cheers

Gavin

Brian Hope · Post by **Brian Hope** » Tue Oct 12, 2010 11:41 pm

AT155 is solid state so this one could be a reasonable deal. Don't think it's worth buying a new A/C, better to pay the extra and get a Mode S.

Gavin Bell · Post by **Gavin Bell** » Wed Oct 13, 2010 10:14 pm

Hi Brian, have contemplated that, but the premium is another £500 and at the moment would for me be better spent on a B&C starter. I know mode S is on it's way, but requirement is probably 3 years away?

I suppose there are different exteremes of view ranging from "don't need a transponder" to "need mode S" and everything in between.

My view is that I want reliable long term equipment that will enable me to get a transit and to enhance safety where possible.

So, if I buy a good Mode C, will it be defunct in 3 yrs time?

Will look at the 155 spec

Cheers

Gav