Flycom FH-1 microphone specs

Mayfield

Mayfield

Gold Supporter
Joined
Oct 30, 2003
Messages
2,481
Location
Avondale, Arizona
Aircraft
Aero SP AT-4 (Gobosh 700X), TAG Titanium Explorer
One of my Flycom FH-1V helmet mic capsules has apparently failed. Tower reports that he is receiving carrier only, no modulation. I have examined all the wiring, and it appears intact. Reception is still fine.

The Flycom website had the mic specs, but it appears they are no longer in business. The Glenmark group is unresponsive to queries. Did MicroAvionics take over the Flycom line?

It is not the FH-1V GA. I use an adaptor from the Flycom plug to GA plugs.

My memory (suspect) tells me it is a 2.2K ohms electret mic.

The helmets worked really well until the mic failure.

I'm sure I could find one on Amazon if I knew the specs.

I have forgotten the info for the mic capsule. Anyone know what I need?

This is similar to the problem I had last year. I did not keep adequate records of the mic specs/

Thanks,

Jim
 
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Wipe headset and ear seals with a mild soap and water mixture only. NEVER IMMERSE
ANY PART OF THE HEADSET IN WATER. Although the microphone is water resistant, to
ensure a longer life, keep the microphone away from moisture, when possible.
Do not store in direct sunlight or in areas of high temperature.

Specifications​

Headsets
Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . 104dB re .0002 microbar @ 1000 Hz, 1 mW
Frequency Response . . . . . . . . . . . . . . . . . . . . . . . 100-17,000 Hz +5 dB in 6 cc coupler
Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 ohms nominal
Impedance (FH703) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 ohms nominal
Weight without cable (FH701, 702, 704) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.9 oz.
Weight without cable (FH703) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 oz.
Weight without cable (UH701, 702) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15.9 oz.
NRR (all except FH703) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24dB
Microphone
DC Bias Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16 volts, not polarity sensitive
Source Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 to 2200 ohms
Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . 370 mV @ 114 SPL re .0002 microbar
Frequency Response . . . . . . . . . . . . . Optimized for speech clarity and noise reduction
Max. Amb. Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . . . 125dB SPL re .0002 microba
 
Mayfield said:
One of my Flycom FH-1 helmet mic capsules has apparently failed. Tower reports that he is receiving carrier only, no modulation. I have examined all the wiring, and it appears intact. Reception is still fine.

The Flycom website had the mic specs, but it appears they are no longer in business. The Glenmark group is unresponsive to queries. Did MicroAvionics take over the Flycom line?

It is not the FH-1 GA. I use an adaptor from the Flycom plug to GA plugs.

My memory (suspect) tells me it is a 2.2K ohms electret mic.

The helmets worked really well until the mic failure.

I'm sure I could find one on Amazon if I knew the specs.

I have forgotten the info for the mic capsule. Anyone know what I need?

This is similar to the problem I had last year. I did not keep adequate records of the mic specs/

Thanks,

Jim
Click to expand...

Larry my ex-partner got helmets from Flycom delivered to him a few weeks back. Their website is fubarred for some reason but believe they are still in business.
 
Hey Jim, if you order a new mic, - please get one for me also in same shipment & we can share costs.

I got 2 mics spare, years ago (2020) -( after overzealous sanitizing during covid )and had a spare on hand after repairing one - which stayed with dear Thomas Fernandez who had my 2 large size helmets that were not functioning properly - he had both working without replacing the mic & kept the mic in payment for his labor - unfortunately he passed away soon after and I was not quick enough to ask his daughter about locating it in his electronics tools before his house was cleaned out & sold!
Now my large Flycom helmet mic is not working again - I need a new replacement! Passenger can hear me - but cannot speak back! (Other headsets plugged in - work perfect!)
I'm down-under until Dec 4th - will send payment when I get home .
Thanks C.
 
Mayfield said:
One of my Flycom FH-1 helmet mic capsules has apparently failed. Tower reports that he is receiving carrier only, no modulation. I have examined all the wiring, and it appears intact. Reception is still fine.

The Flycom website had the mic specs, but it appears they are no longer in business. The Glenmark group is unresponsive to queries. Did MicroAvionics take over the Flycom line?

It is not the FH-1 GA. I use an adaptor from the Flycom plug to GA plugs.

My memory (suspect) tells me it is a 2.2K ohms electret mic.

The helmets worked really well until the mic failure.

I'm sure I could find one on Amazon if I knew the specs.

I have forgotten the info for the mic capsule. Anyone know what I need?

This is similar to the problem I had last year. I did not keep adequate records of the mic specs/

Thanks,

Jim
Click to expand...
Hi Jim. The following relates to the FH-1V series which was for the ultralight market (Not GA)
They used an amplified electret mic circuit on the VOL control pot at the side of the helmet rim in the early 2000s and I share the details with you below.
From memory I used to source the mic insert from RS components, but Mouser may also have them.

Regards.........Chook.
 

Attachments

Chook said:
Hi Jim. The following relates to the FH-1V series which was for the ultralight market (Not GA)
They used an amplified electret mic circuit on the VOL control pot at the side of the helmet rim in the early 2000s and I share the details with you below.
From memory I used to source the mic insert from RS components, but Mouser may also have them.

Regards.........Chook.
Click to expand...
Hello Wayne,

The hand drawn amp schematic. The resistor values you have listed I’m guessing translates as: 121 = 120 ohm, 392 = 3.9K ohm, 472 = 4.2K ohm, 564 = 56K ohm, 822 = 8.2k ohm. What are the missing values for the potentiometer and capacitors, and the number of the one transistor?

Wayne
 
Wayne squared, and probably Bobby and Abid, and Jeff:

Is this close enough?

6 x 2.2mm Electret Condenser Microphone MP3 Microphone Accessories

Characteristics:

Working Voltage:1.5V~10V DC
Impedance:2.2kΩ (Maximum)
Current Consumption:0.5mA (Maximum)
Sensitivity:-48dB ~ 66dB
Frequency response: 50 ~ 20kHz
S/N Ratio:>48dB
 
I removed the electronics and original mic/boom and replaced with David Clark stuff
 
okikuma said:
Hello Wayne,

The hand drawn amp schematic. The resistor values you have listed I’m guessing translates as: 121 = 120 ohm, 392 = 3.9K ohm, 472 = 4.2K ohm, 564 = 56K ohm, 822 = 8.2k ohm. What are the missing values for the potentiometer and capacitors, and the number of the one transistor?

Wayne
Click to expand...
Hi Wayne.
Yes your resistor conversions are correct.
The variable resistor (potentiometer) is 4.7K ohms. Note that the potentiometer only affects the volume presented to the helmet earphones and does not have any control over the microphone circuitry. Flycom just conveniently used the same PCB.
The caps and transistor are surface mount units which I did not get the values of at the time. If you are familiar with these components and their small sizes at my age I usually use a microscope to get their values and I didn't want to dissect the customers brand new helmet at the time.
The caps rarely have their values displayed but would be in the 0.01 or 001uF value range.
I have attached another of my personal schematics to show you the overall cct and how they fit together.
That particular one I used to install ANR circuitry into many gyro helmets here in Australia before Aircraft Spruce got hold of the distribution rights and made them completely uneconomical. I now recommend that the guys use in ear moulds or CEP in ear expanding foam which works as well or better at a fraction of the price. Sorry I am deviating from the subject.

Now getting back to the original circuit, the transistor appears to be in Common Collector (emitter follower) mode. This will give you a low voltage gain, a high current gain, a medium power gain, a zero phase change, a high input resistance (the mic on the base cct) and a low output resistance into the emitter. Remember that the power is supplied to this circuit along the ring of the helmet plug. This gives a a good signal swing across the power supply for the transceiver to collect and feed into the transmit section.

Regards.......Chook.
 

Attachments

Mayfield said:
Wayne squared, and probably Bobby and Abid, and Jeff:

Is this close enough?

6 x 2.2mm Electret Condenser Microphone MP3 Microphone Accessories

Characteristics:

Working Voltage:1.5V~10V DC
Impedance:2.2kΩ (Maximum)
Current Consumption:0.5mA (Maximum)
Sensitivity:-48dB ~ 66dB
Frequency response: 50 ~ 20kHz
S/N Ra
Click to expand...

Jim, I'm wondering if this conversation would be better in the Avionics/Instrumentation section?

I have just checked the mic insert ABM-711-RC and it is available from Element 14 for $2.54 (Aussie dollars) This particular microphone is distributed by an English firm Alan Butcher components limited. I notice that Newark electronics (an American distributer?) also sells them.
Both distributers prices seem very reasonable, so the only decision you really need to make is who charges the least in postage.

Be careful substituting microphones as this particular microphone has an unusual frequency response graph. See attached spec sheet.
I do recall sending Alan Butcher an enquiry which subsequently went back to the manufacturer about this graph but their reply was not clear as to why there are 3 graph lines when generally there is only the one centre line. The L value was not explained but may relate to the distance from the microphone within the test chamber. And what is very interesting is the inversion because of this.
Indeed this may further reduce background noise which for our gyro or open noisy cockpit situations is a welcomed feature.

Regards.....Chook.
 

Attachments

Joe Pires had a source for replacement mics. A google search may help find the post.
 
Thanks,

What a memory I have! Joe provided the part number in response to my question several months ago. Geez!

Jim
 
The volume control pot in my Flycomm was 2.2k ohms.
 
Bearing in mind that my electronic savvy is demonstrated by sometimes recognizing the hot end of a soldering iron;
I installed an electret condenser microphone from Amazon. The Amazon info is:

HiLetgo 10pcs Electret Condenser Microphone 52dB MP3 Microphone Accessories 6x2.2mm​


They were roughly 59 cents each.

Tower reports my transmissions, while flying the pattern in my TAG, are loud and clear without objectionable background noise.

I don't know how long it will last, so I will purchase the ABM-711-RC to have it in stock.

Jim
 
Mayfield said:
Bearing in mind that my electronic savvy is demonstrated by sometimes recognizing the hot end of a soldering iron;
I installed an electret condenser microphone from Amazon. The Amazon info is:

HiLetgo 10pcs Electret Condenser Microphone 52dB MP3 Microphone Accessories 6x2.2mm​


They were roughly 59 cents each.

Tower reports my transmissions, while flying the pattern in my TAG, are loud and clear without objectionable background noise.

I don't know how long it will last, so I will purchase the ABM-711-RC to have it in stock.

Jim
Click to expand...
Thanks for the update Jim.
Just for my interest, what radio/intercom combination are installed in your TAG?
The other test is to use the intercom system using both of your helmets and see if you can detect any difference in the speech quality between them. I am glad that you have progressed this far. Keep up the good work.

Regards...Chook.
 
Thanks Chook. I'll check that.

I use the Funke radio/intercom


Jim
 
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Update.

Flew this morning. The intercom seems to work acceptably from both positions.

Hopefully the installed mics will continue to work for awhile.

It helps to remember you have a volume control on the helmet audio. If you forget, and have the helmet audio turned down, you have to turn the radio volume way up, have no audible sidetone when you transmit, and the intercom between stations doesn't work. Not that I would know anything about being that dumb.

Jim

PS: Vance, that's self deprecating humor.
 
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Mayfield said:
Update.

Flew this morning. The intercom seems to work acceptably from both positions.

Hopefully the installed mics will continue to work for awhile.

It helps to remember you have a volume control on the helmet audio. If you forget, and have the helmet audio turned down, you have to turn the radio volume way up, have no audible sidetone when you transmit, and the intercom between stations doesn't work. Not that I would know anything about being that dumb.

Jim
Click to expand...

You should ideally keep your Flycom volume to about 60% and then control the volume from your com. That s supposed to give you best noise reduction from Flycom
 
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