In reply to LookingNorth,
I am afraid the radios, specifically the RT2 UHF and VHF sets controlled by the 1st Pilot, were most assurredly not alright.
The howling noise on UHF almost blanked out all speech. In addition, there was a whistling noise with weak sidetone on the VHF radio.
The RT1 system, controlled by the AEO, which only uses UHF, was O.K. However, the Garmin VHF at the AEO position, although clear seemed to have weak sidetone.
On Tuesday last, I took all the components of the UHF and VHF RT2 system, including Interface unit , junction box and cables, to the nice chaps at Serco's Fairy Glen, who checked them out on their test equipment. The UHF radio had a defective card causing distortion when the test tone was injected. The sidetone line is apparently shared by the VHF radio too, both are mounted on a common crate, and this is thought to have affected the VHF too. After repair and testing, the entire system was connected together on a systems rig and tested satisfactorily. RT2 components will be refitted on Monday next as soon as I can get to do the job.
The Garmin VHF is the responsibility of Marshall Aerospace and it is believed that their design boffins have come up with a fix which hopefully will be fitted very soon.
Hope that clears things a bit
