Icom F9011 Very Noise Power Supply

BlueDevil · #1 (**permalink**) 03-01-2017, 1:33 PM

We have about 20 Icom F9011S portable radios out in the field. We noticed very quickly that this radio sees to have a very noise power supply. When transmitting with either the internal mic or an accessory attachment a very annoying background noise/hum in the received audio is easily detectable by even the most deaf of Dispatchers. When receiving audio through the internal speaker the noise/hum is hardly detectable or noticeable however when using a accessory mic and ear piece attachment (Pryme SPM-1300 with PA-520 quick disconnect adapter) the noise/hum is easily detectable in the ear piece causing an almost immediate headache.

Has anyone else noticed this? Are there any easy solutions? I have tried tweaking and fine tuning about every programming adjustment that I can. We are using a conventional analong VHF radio system.

cmdrwill · #2 (**permalink**) 03-01-2017, 3:00 PM

Are you using the correct factory antenna?, an incorrect antenna will cause noise on transmit, RF feedback.

Pryme spkr/mics are not the best, get OEM ICOM.

BlueDevil · #3 (**permalink**) 03-01-2017, 5:14 PM

Here are some YouTube videos of the very basic testing I have performed. Nothing super scientific however the noise/hum I am referencing should be obvious in the videos. The only video or recording I was unable to obtain was the audio coming out of the ear piece. Below is a picture of the radio and accessory equipment the department has elected to use.

https://youtu.be/cTyEM8a3nHQ
https://youtu.be/MP8fPEgapyU
https://youtu.be/lqP7xaLZglQ
https://youtu.be/mltOIH8HVFQ
https://youtu.be/X-UrrHeHJRA
https://youtu.be/mLi-fiah-IA

BlueDevil · #4 (**permalink**) 03-03-2017, 3:04 PM

After further testing it seems that the F9011 is continuously transmitting a 1000Hz tone while transmitting. I assume it is the same tone heard in the audio while the radio is receiving a signal.

BlueDevil · #5 (**permalink**) 03-31-2017, 10:43 AM

As an update we are trying out some different connectors and lapel mics. After several correspondence with Icom they are certain that the background noise/hum is not coming from their F9011 radio.

We purchased the Icom OEM Quick Disconnect Adapter, part number AD-118. To my surprise it came with a Ferrite Core attachment. Why would they need to include that?

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