Thorp Air Command - T18.net

As most that attended Kentucky Dam know, Bob spent most of the time on the gound trying to fix/locate an replacement alternator. Guess what, I had the info on my hard drive all the time, so I thought I would share the info.
It is a Nipon-Denso alternator
Autozone/Advanced Auto part number 14184 or Beck Arnley 186-100
The regulator is a Ford solid state F7078, several regulators can be adapted. This alternator comes in several different amperage output, from 35 to 95 amps.
I might add that Mark Landoll that used to sell this setup has retired.

Adding to Bill's post: The alternator comes off of a late 70's Honda Civic and was used in various amperages. The most common seems to be the 35 amp version. On a related subject, I made it home with the battery by shutting down all but the essential equipment.

I replaced the battery when I got home. To my amazement, my battery had been in service for 7 1/2 years! Of course when I went to the battery store, I was informed that they don't make that battery any more. I fact, all batteries of that type are now made in China.

The closest match I found was the Interstate DCM0035. It is a sealed, air transportable AGM Deep Cycle 35 AH mobility scooter unit. AGM means that the plates are separated by a fiber glass mat. This is what allows the battery to be repeatedly charged and discharged without failure. This battery does not need to be boxed or vented which makes it ideal for our use.

_________________
Bob Highley
N711SH
SN 835
KLAL

I have the same alternator on 55RC. I just replaced it but now I have a hum in one of my radios. It is definatly from the alternator because when I swich it of the hum stops. But I do not understand why it only affects one of my two radios. And the hum is there all the time but gets real loud when receiving. Again only in my primary radio.

Any ideas are welcome.

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Matt Smith
Des Moines, IA
55RC

Only one radio has the noise ? All you did was change out the alternator...nothing with the radio wiring ? Does the "new" alternator have a radio filter installed (talking about a filter for a car radio). I believe you can get a car alternator with and w/o a filter ? Does the hum increase with engine speed ?

RB

Yes that is what is hard to understand only one radio has the noise. All I did was change out the alternator. I do not know if the new alternator has a filter or not. There is a filter of some sort wired to the output cable. It is about a 1" diameter and about 1.5" long and only has one wire. I will need to do some more testing but I do not believe the hum increased with engine speed, however it did get very loud when receiving a transmision.

I am planning on changing where the ground wire connects. Right now it connected to a bolt on the back of the alternator like the old one was. I thought I would connect it to the engine block to see if that helped with the noise.

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Matt Smith
Des Moines, IA
55RC

Matt - check the ground on the offending radio as well - I have gone through three static/hum/transmission issues now where the problem was simply cleaning the grounding metal.

Ok, I changed the ground location on the alternator and the radio noise went away. But now the amp meter bounces from 5 to 20. Before the old alternator quite to would pulse some. Say it would be below 5 amps and it would pulse (every second or so) to above 5 amps. But this one moves much farther and faster. Any comments?

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Matt Smith
Des Moines, IA
55RC

Regulator??

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Bob Highley
N711SH
SN 835
KLAL

Strobes on or off?

What is your Volt Meter reading ? Do you have an external voltage regulator ? Any equipment that draws a big load and cycles on an off ? Is this a "new" alternator ? Or a rebuilt one ? If it is a rebuilt unit and has an internal regulator, could be the regulator. Wouldn't be the first time I've gotten a rebuilt unit for my car and it was bad.

RB

Thanks everyone. Strobes were off. External Regulator.

I decided to button her up and fly. When I started her up the amp meter went to the peg for 5 to 10 seconds and then came down and started the swings but not as bad before. By the time I got to the end of the runway and the run up done it was setting pretty steady on 10 amps. I flew for about 40 minutes and it showed about 10 amps the whole time. The battery was probably down quite a bit due to the test starts and the two months I haven't flown, however, I did expect it to be charged up after 40 minutes.

Thanks again for all the comments.

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Matt Smith
Des Moines, IA
55RC

I highly recommend you buy a Battery Tender trickle charger. It will increase the life of your battery by years.

I use the Genius G750 charger. It is made for AGM batteries....like my PC-680. About $40.00 on Amazon. I have it wired to the battery with the supplied pig tails that allow me to quick disconnect. I would stay away from the HF barn burner battery charger/maintainers !

RB

Hello everyone,

I flew again Saturday and alternator works great. Guess I was just over critical. Started her up and it charged clear over for a second or two and then started to bounce some. After short while (probably 3 -5 minutes she was sitting right on 10 amps. 20 mintutes after departing she was on 5 amps.

Hi Jim,

I have a Battery Tender Jr. just have not connected the leads yet. Planning on doing that during inspection next month.

Thanks everyone for your comments.

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Matt Smith
Des Moines, IA
55RC