Aviasport Rotor tach Wiring issue?

[AirCommandPilot]

I'm getting a very inconsistent reading from my new rotor tach. Everything seems to work if I just pass a piece of steel over the sensor in a rhythmic manner, but when the engine is running, it seems to get very chaotic. Should I be using shielded wire from the sensor to the tach?

 

[coyotekyk]

I had the same problem. I sent the gauge to Aviasport and they told me it was not repairable, and I that should buy another one.
I finally installed a bike computer and I´m very happy with it.
A friend of mine gets also chaotic readings in his ELA with this gauge...

 

[Chris Burgess]

I would suspect you have an electrical feed running too close to the wires that sense the tach. A bicycle tach actually works great an only cost in the neighborhood of $15-$20. You still need to keep the sensor line away from other strong electrical fields (shielded wire may be best) I used one for about 18 years on my two-place and about the same on my single and glider. The bonus information you get alone is worth it (RRPM of course, total turns, time turning, average rrpm, max rrpm, current time) pretty "cool" info and "cheap". Only get current rotor rpm on a normal "expensive" tach.

 

[helipaddy]

Put a 5 or 10K ohm resistor between the rpm input on the gauge and ground. (Between pin 2 and pin 3)

 

[coyotekyk]

Put a 5 or 10K ohm resistor between the rpm input on the gauge and ground. (Between pin 2 and pin 3)

I already tried this, but nothing changed.
I believe that much of the problem is the interference of the rotor itself on the instrument.

 

[helipaddy]

We also got erratic readings on our Aviasport and changed the ELA's rotor tach to a MGL infinity RV1. Works perfectly now.

http://www.mglavionics.com/html/infinity.html#RV-1

if you want a Colour screen check out the MGL Vega range.

 

[AirCommandPilot]

I had an MGL E-1 and Flight-2 on it until the Flight-2 just died without warning. I only had 14 hrs on the gauge. Sent it back to MGL, they said they couldn't fix it, but they would give me a 15% discount on a new one. With the discount, I would have to paid more than the original cost of the gauge.
I decided to go with analog gauges instead. I like having a sweeping needle vs having to read a number.
On that note, I have a good MGL E-1 for sale.

 

[Danough]

I would suspect you have an electrical feed running too close to the wires that sense the tach. A bicycle tach actually works great an only cost in the neighborhood of $15-$20. You still need to keep the sensor line away from other strong electrical fields (shielded wire may be best) I used one for about 18 years on my two-place and about the same on my single and glider. The bonus information you get alone is worth it (RRPM of course, total turns, time turning, average rrpm, max rrpm, current time) pretty "cool" info and "cheap". Only get current rotor rpm on a normal "expensive" tach.

I know this is an old thread, but Chris Burgess can you tell me how you would calibrate a bicycle computer such as this? It would read in distance, and we need actual RPM. The calibration procedure on the ones I looked at on Amazon have you turn the bicycle wheel one revolution and that’s it.

Thanks!
Danough

 

[Vance]

Chris Burgess retired to Florida but still visits the Rotary Wing Forum occasionally.

My suggestion is to contact the manufacturer and ask them.

Calumet Manufacturing sells bicycle speedometers for rotor tachometers and may be able to help you.

https://www.calumetmanufacturing.com/

A rotor tachometer is very important on a helicopter and I would prefer analog and one with the engine rpm on the same instrument so you can do the split more easily.