Great replacement bulbs for Piper Arrow II landing gear indicator lights.

Richard T Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

I bought 10 of these several years ago to put into the buttons of our Continental 816R and QEI FMQ 10,000 transmitters. They remain bright and steady all these years later. The bipolar nature and wide voltage range allows these bulbs to operate well no matter what socket I put them into on these transmitters. The transmitter manufacturers basically told me I was SOL when it came to replacement lights, but Spruce had these and Im buying more now to try in our Wheatstone Audio Arts R-60 consoles. Im hopeful at the 5 Volt level, the light will be as nice as the original LED lights the console came with 25 years ago. For 30 Volt use, though, I think this is the ONLY choice for your T1 3/4 replacement. And the price is one of the best on the internet for any LED bulb of the miniature variety. There might be rare cases where these bulbs wont work, but Ive had them work fine in AC or DC sockets from 24 Volts to 28 Volts. They stay bright and steady and dont flicker or do unpredictable things in push button actuator switches on these transmitters. The old incandescent ones were always flickering or burning out within a couple of months. These are well worth the try.

These are an excellent replacement for the original bulbs. They are very bright and low energy draw. Makes it easy to see gear position during the day.

Sean D Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

Works great and draws very little power and nice brightness.

Jay S Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

Works well and a fast, well packaged delivery.

Jay S Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

Excellent product!

They are bright and easy to see Them during bright sun light.

Excellent product. Exactly what I needed, where I needed it, superb shipping and reasonable price.

Very Good. Just as I ordered.

These LED lights are brighter than the incandescent bulbs they replaced. In my case, I have bulb cases with adjustable eyes, so I’m not worried about it. You can see these LEDs better in daylight. The incandescent bulbs got very hot, but the LED lights are cool. The LEDs should last much longer than the incandescent bulbs.

The reason these lamps will not work in a compass is because a compass light fixture is wired backwards than a normal fixture. This is due to the way the lamp is inserted in the fixture. The positive post in a compass fixture is inside away from the frame, and touches the outside circumference of the lamp (normally the ground). The ground is the cover over the lamp, which touches the center lamp electrode. If it was wired conventionally, you would touch the case and get a shock. LEDs are polarity sensitive.

This was the only site I found that carried an LED lamp of this shape that was described as being a bi-polar lamp. The new lamps fit well and have worked in all our applications on broadcast equipment panels.

These bulbs are an excellent replacement for the GE 330, but be aware that they will probably overwhelm green or amber lenses. All I can see thru my amber warning light is a bright white. I dont usually fly at night so this is fine. My amber warning lights are not the dimmable kind. I have a dimmable red lens warning light, and the red shows ok and the bulb seem to dim.

Work great in Continental 616R series FM transmitters as direct replacement for the incandescent midget lamps in the filament on/off and plate on/off buttons. They are super bright, so only one bulb per button is needed, even though the button frame will accommodate four per button. These also work great for the panel lights in a QEI FMQ 10,000 transmitter! Super versatile, super bright, super cool and the price is super right.

Plenty bright as a 327 replacement in a 28 volt system. Doesn't appear to generate as much heat as the original incandescent lamp.

Used as a replacement for GE-330 12V landing gear indicator lamps. Brighter than the incandescent lamps, not sure if they can be dimmed or not, mine stay full bright.

Much brighter in my original landing gear down indication bulbs. Now I can see the lights even when the sun is shining on it.

Look great but these did not work for me. I think the size is slightly off

Moon S Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

Ordered 6 bulbs, 5 of 6 worked, one did not.

These work as a replacement for GE327 but beware: they DO NOT DIM. In my panel the 3 gear lights are actually too bright at night.

Ordered to replace the landing light bulbs in my piper. They fit in the lenses, and look like they are making contact, but wont light up. I assume the polarity must be backwards, but I also assumed thats what Bi-polar and any polarity meant. Maybe bi-polar refers to them sometimes working and sometimes not. They work fine in the warning lights, so I suppose thats where theyll get used someday. I didnt find them to be any brighter than the incandescent bulbs either, which was also disappointing.

Great specs, but 2 out of 3 did not operate when powered up, have to be reordered

The bulb works as described when powered up on the bench however this bulb does not fit in my compass. The shape of the plastic LED stops it from being inserted far enough into the compass to close the cover (tip contact).

I just received my replacement bulbs from my initial shipment as 20 units were damaged at at the base of the bulb due to, (in my opinion), poor construction methods. Although these bulbs functioned fine, (except one), most were damaged at the base, (torn metal), or the Mica separator was protruding out so far that the assembly would not close once the bulb was installed in the holder. Just received my 20 replacement bulbs and, although they are slightly better, some bulbs still displayed poor quality control issues and I ended up picking out the best of the best and sending back a combination of the initial shipment and the new shipment. If you compare these bulbs with the Sloan LED product, there is no comparison as the Sloan product is perfectly constructed with zero flaws. I ordered 100 of these bulbs as well and could not find manufacturing flaws except that the Sloan LED product is not bi-polar and therefore could not be used in my application. I really like this product and find disappointment that, for the price per bulb, there should be a higher manufacturing standard.

Although I love the idea of these replacement bulbs. I find that the quality control is somewhat lacking. I found a number of these bulbs either damaged at the base, or the Mica electrical separator protruding out so far that my lamp holder would not close properly, or pushed too far in where it would create a short in my application. When considering the cost per unit, these bulbs should be in top quality condition. I have also bought the Sloan LED model and found there build to be far superior, however they are not bipolar and could not be used in my application. I will add that Aircraft Spruce has the best customer service I have seen as they have satisfied my every need in replacing these bulbs. This company is a good example that customer service trumps quality control as I will order from them again in the future.

Bought these since the description says they are bi-polar. They are not. Bought some others from Aero-lites that are bipolar and work properly in a push to test light.

Bob J Verified Purchase

BI-POLAR MINI LED REPL T1-3/4

I bought these as they are described as Bi-Polar, will operate AC or DC, any polarity, 5-28V. They do not work with reversed polarity. Much brighter than incandescents.

Very disappointed with these bulbs. I ordered 3 over that last 6 months and not one worked. Would not work in the airplane or on test equipment when hooked up directly to as 9v battery or 12v power supply. Dont waste your money on these.

Bought three to replace 327 bulbs.. all three arrived DOA. Definitely quality control issues.

Its an LED. Unfortunately the flange is larger in diameter than the equivalent GE incandescent and some of the other LED replacements on the market. It didnt work in my application because the bulb holder is a close tolerance fit. The main section fits into the screw in lens just fine, but the wider flange wouldnt fit into the threaded socket. I carefully polished the flange down on a scotchbright wheel and got it to fit but it still intermittently shorted out the socket internally. I used a different bulb and threw these away. If the flange is a close fit in your socket this is not the LED bulb for you.

I purchased four of these and two burned out within a month. The bulbs that these replace last longer than that. These are too expensive to burn out so quickly.

Tried to use them in the compass. Bought 2 with the intent of one as a spare, however, tried them both and neither would come on. Checked them with a battery and still will not work. Not very happy with the outcome.

Polarity does matter with these. 3 out of 3 did not work in my aircraft. Checked on a battery, they work fine.

These did not work in my 24v MU-2

6 out of 6 of them did not work. Had to return them.