The 24 Hours of Lemons Forums → Lemons Tech → HowTo: DIY radio helmet mic, on the cheap
I am in the process of building some helmet kits. The problem that I am having is the PTT button won't make the radio transmit. I can hear audio great. Does this sound like a Mic impedance issue or do I have a bad car harness/PTT button?
Could be mic impedance, bad/incorrect harness.
What radios and harness are you using?
The radio is a Motorola XTS5000R the harness is from Race City Radios with a Motorola 2 pin radio plug. I had to purchase an adapter for the radio to accept the 2 pin harness. any help is greatly appreciated.
Mic impedance could be your issue. The Motorolas I have worked with have been pretty flexible on my impedance from 150-2200 Ohms. The ground source could be an issue. The mics you are using may be 4400 Ohms or greater which could be an issue too.
Does the radio key up at all? The helmet kit much be plugged in to complete the circuit and key the radio too. If the radio keys up but there is no audio, the mic wiring could be backwards. Try switching you mic wiring. I am pretty sure your mic is an electret condenser mic and if it's wired backwards it won't work.
If nothing is happening, your 2-[in adapter could be bad. I've seen those fail.
I made a system for another team not to long about with the jumper the XTS5000Rs use. I also included a 2-pin adapter since they had an adapter for that too. More adapters means more potential failure points so I prefer to see the harness connected directly to the radio.
How soon do you need this stuff?
The radio will key up from the side of the radio and the radio mic works with the car harness and helmet harness plugged in. I've tried the mic both ways, with and without a 10k resistor. The mic is a cheap computer mic. Is there an adapter for that radio that plugs to the car harness direct rather than the 2-in adapter then 2 pin harness adapter like I'm trying now? All of the components are new, I know that new doesn't always mean that it's good. Thanks for trying to help. Our next race is September but I'll sleep better when this works.
thekingcrab, I sent you an email. Email me your address and I will send you something to try.
email sent
So why exactly can't we use something like this?
http://www.bhphotovideo.com/c/product/8 … phone.html
We've been using this set-up for the last ten races or so with no problems.
I buy a set-up for every new driver.
You can find them on Amazon for $25.
They were only $10 each a few years ago when I bought four kits.
http://www.amazon.com/Midland-AVPH2-Clo … 38682QX66Y
Wreck Faster wrote:So why exactly can't we use something like this?
http://www.bhphotovideo.com/c/product/8 … phone.html
We've been using this set-up for the last ten races or so with no problems.
I buy a set-up for every new driver.You can find them on Amazon for $25.
They were only $10 each a few years ago when I bought four kits.
Trekkor, obviously you can since you are.
The 24 Hours of Lemons Forums → Lemons Tech → HowTo: DIY radio helmet mic, on the cheap
