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No electrical system, which road to take with a radio install?

gravytime

Registered User
We are finishing up the complete restoration of our 1952 L-18C and and I am looking for ideas on the best radio/intercom to install. It has no electrical so we are considering a wind generator to keep the battery charged. My mechanic recommended the Flightline FL760 and said he could install it in the wing root. Anybody else without electrical systems have any ideas or any pictures of their set up? Is a wind generator worth it? Thanks for the info.
 
I saw a really nice install in a J-3 at Twin Oaks in Hillsboro Oregon. Give the airport a call and see if they would send you a picture of Bob's.

I don't know how much time you plan to fly each day, but consider a solar panel for charging instead of the wind generator. While the wind gens are neat, it would be much more simple to put a solar panel in with zip ties. If you are flying lots you can put a charger on at night also.

Simple is probably better!
 
Simple is better. I run a handheld Terra "Blue Brick" radio, a Garmin GPS and an intercom with an Earth X 16AH battery mounted under the seat.
It gets plugged into a maintainer once a month, maybe. The solar charger would probably work, too. Depends on how talkative you get.
 
yep, consider no charger at all, maybe a aa battery pack backup just in case, and a small motorcyle type battery, it will go a long time. maybe bob t will tell about his setup.
 
But then, in the big city, you have an engine driven charging system and have to comply with all the big boy rules.
 
But then, in the big city, you have an engine driven charging system and have to comply with all the big boy rules.
I have an A5, an intercom and a Garmin 510 all source to a compact rechargeable 12 volt cell in the baggage compartment. The set up works really well and one can go for 2 to 3 days without recharging.

Sent from my SM-G930R4 using SuperCub.Org mobile app
 
I have installed three GTR-200 radios - two Cubs and a Stearman. I am pleased.

The Garmin takes a lot more juice than does my SL-40. We got seven tach hours at first on a 7 AH battery. But then either all my batteries got weak at the same time, or the radio got more demanding, and we started getting only one tach hour per charge. My SL-40 goes for five hours on the same battery.

Right now we are running two 7 AH batteries in series for 24 volts and getting 12 tach hours of continuous pattern work between charges. I consider that ok.

It has one other flaw - not enough RF squelch. Other than those two things, the GTR-200 is the very best aircraft radio I have ever used. And installation is almost trivial - you do need a professional grade crimper and some knowledge of shielding.

Oh - best thing? With David Clark 10-13.4 headsets and Oregon Aero muffs (outer hole taped over) the internal intercom cannot be beat! Even at full power in the Stearman. No need for the leather muffs in the open J-3. Just perfect!

Wanna picture?
 
Whatever you wind up with, you’ll need an external antenna. I used a 121.5 MHz ELT antenna taken off an airplane. With the Icom A-5 it worked great with a Lo ion battery, no charger. Antenna mounted on left wing root fairing.

MTV
 
I agree with MTV

But I discovered an exception. One of my students has a Chief with the newer Icom portable. The antenna got taped to the windshield - a desperate attempt by me to have at least some communications during a transcontinental flight. Somehow it worked! This kid is flying in the LA basin with it, in and out of SMO, and getting really good service from SoCal. No transponder! Brand new Sport license.

I am still amazed. Must be a fluke. No ground plane at all. Lots of parasitics. Do what Mike says, and don't depend on luck.
 
If the antenna is separated from the radio but remains connected with coax cable, the coax and radio case can be volunteered to be the other half off the antenna. They act like a typical ground plane might, but sometimes are not as good. Radio frequency current can find a way to flow on the outside of the coax unless suppressed. The length of the combined coax and radio can be critical for best performance at the frequencies we use in aircraft. And if the portable radio is attached via conductive mounts to the aircraft metal then that can add to the antenna setup, just as we do when holding the radio in our hands.

So yes it works...RF often finds a way to get transmitted. There are signal strength meters that at a distance can measure differences in setups but few would bother to fine tune an installation. They'd rather spend time and money on other things for their aircraft.

Gary
 
I agree with MTV

But I discovered an exception. One of my students has a Chief with the newer Icom portable. The antenna got taped to the windshield - a desperate attempt by me to have at least some communications during a transcontinental flight. Somehow it worked! This kid is flying in the LA basin with it, in and out of SMO, and getting really good service from SoCal. No transponder! Brand new Sport license.

I am still amazed. Must be a fluke. No ground plane at all. Lots of parasitics. Do what Mike says, and don't depend on luck.
Bob, What is below the antenna? How about the wraparound cowl and top of the instrument glare-shield? That is your ground plane.
 
Typically one would want a ground plane at the feed end of the antenna, not a foot away. The original owner had the rubber ducky taped horizontally to his front spar cover. He said it worked 60 miles out. I chose not to believe that and selected vertical polarization and not taped to a piece of aluminum. I taped it to the upper center of the windshield, fed with coax from the top.

I did not expect it to work. El Paso was prepared to let me through nordo.
 
For example if the antenna is taped vertically to the windshield then nearby is usually some airframe metal - windshield frame or structural tubing. Remove the coax feed line's coax cover from a portion and put a metal clamp over the exposed shield and bolt it (metal to metal contact) to any existing fasteners. A hose clamp would also work. Now there's a counterpoise of sorts for the antenna to work against. If it hears ok it should transmit ok, but an SWR meter at the radio would know more about the system.

Gary
 
We are finishing up the complete restoration of our 1952 L-18C and and I am looking for ideas on the best radio/intercom to install. It has no electrical so we are considering a wind generator to keep the battery charged. My mechanic recommended the Flightline FL760 and said he could install it in the wing root. Anybody else without electrical systems have any ideas or any pictures of their set up? Is a wind generator worth it? Thanks for the info.

Depends on what route you want to take.

Panel mounted equipment will give you better performance. Radios like a Becker or a Microair (not a big fan of the FL760) will give good power out, easy volume and squelch control, and extras like monitoring a second frequency. They also mount in a small instrument hole, without a mounting tray. If you use an intercom such as the PM501/PM500EX, you'll get good power to the headsets, separate intercom volume control and intercom squelch control with an external knob. These small units use a quarter amp or less at rest and two to three amps while transmitting. So if you go with just a battery for power, recharge it after flying or swap it out with a fresh battery.

If you go totally portable, you don't need to mount anything. Through the radio in your shirt pocket, or velcro the radio and intercom in handy spots. Run Duracell batteries and keep spares on board. The downside is usually less range on transmission, prone to be noisey, and lower power to the headsets.

Either way you go, make sure to use an external, properly mounted antenna.

Web
 
Thanks for the info. I’ll take a look at Becker and Microair and probably skip the wind generator. Already planning an external antenna. Any recommendations for the best battery to power it?
 
Thanks for the info. I’ll take a look at Becker and Microair and probably skip the wind generator. Already planning an external antenna. Any recommendations for the best battery to power it?

Calculate the size according to the load you'll put on it. Look at AGM style batteries. Stands for absorbent glass mat. Very compact and hold a charge well.

Web
 
Don 't recommend Flightline. Mine worked great for 11 months. Then it smoked. No real service or warranty. Out the $800.
 
As to a specific battery - we have been using the Yuasa 7 ah cells. I think they are AGM. I had a failure yesterday, but it was 5 years old. The one driving my SL-40 has six tach hours on it, continuous pattern work. I keep two fully charged spares on the workbench, and one in the Cub.

But - we are using the PC-545 for the J-3 starters. They give between 50 and 75 starts per charge - I guess depending on how carefully I charge them. I am going to bite the bullet and get an Odyssey charger, just to make sure.

And I am giving consideration to using the 545 as the radio source, or maybe as a backup. All it will take is a fuse, a DPDT switch, and me getting off the couch. We have been using the Odysseys for two years, almost, with zero problems.
 
I installed a GTR-200 as Bob did and loved it as well. I do believe it likes power though and if you’re the talkative sort (flying with friends) it will start transmitting “with reduced power” as the battery voltage drops.
I’m a believer in a wind generator, but on the experimental side.


Sent from my iPhone using SuperCub.Org
 
Thanks for the info. I’ll take a look at Becker and Microair and probably skip the wind generator. Already planning an external antenna. Any recommendations for the best battery to power it?

I wouldn’t necessarily eliminate the wind generator. Consider your mission. If you’ll spend many nights away from home, the wind generator could eliminate some angst re: battery life. If you’re likely to spend most nights at home where you can plug in to a battery maintainer, maybe not on the generator.

I think if if I were to do it again, I’d install a wind generator.

MTV
 
Here is a homemade wind generator which puts out 15+ amps. Total installed weight 5 lbs. Works like a charm.

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Still using my 25 YO Icom 21 in my J4

Glenn

But you never turn it on!:lol::lol:

Pete, nice set up. What type of an alternator or generator did you find for that?

I still like Solar panels for just infrequent or small radio use- less moving parts and easy to replace at any auto store.

Great ideas all!
 
It's a dynamo and regulator from a Kubota tractor with a homemade propeller made from three layers of 3/4" plywood.
 
I have flown several Cubs with wind generators. Giant pain for pattern work - we had to charge the big Odyssey before every flight. In contrast, my SL-40 just passed seven tach hours sucking on a 7 ah motorcycle battery. The big problem is the speed at which the generator begins putting out enough voltage, and the giant sucking sound at the master solenoid.
 
Bob, Must be the type of wind generator you are using. Mine will put out juice by only running up the engine.
 
And likewise with my version of the same unit, output was alive about rotation. Once I installed it I never charged or removed the battery again. And I ran a small battery.

This unit is _not_ the 1940's vintage generators with 2 amps output at 80 mph. Those collector items only belong in a bin or wall mounted for art.
 
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