Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

BOSE A20 & THE EC135

Wikiposts
Search
Rotorheads A haven for helicopter professionals to discuss the things that affect them

BOSE A20 & THE EC135

Thread Tools
 
Search this Thread
 
Old 6th Sep 2021, 13:31
  #1 (permalink)  
Thread Starter
 
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
Posts: 1,297
Likes: 0
Received 18 Likes on 4 Posts
BOSE A20 & THE EC135

Hi All,

Does anybody know for certain if the EC135 intercom system is LOW or HIGH impendence? We are looking to pruchase some Bose A20 headsets for the machines.
I have a A20 that I used in the EC225 and it does not work in the EC135. I seem to remember that the EC225 was LOW impendence and therefore am assuming the the EC135 is HIGH.

I would appreciate anyone's experience of this issue.

DOUBLE BOGEY is offline  
Old 6th Sep 2021, 16:18
  #2 (permalink)  
 
Join Date: Dec 2003
Location: The South
Age: 58
Posts: 517
Likes: 0
Received 4 Likes on 2 Posts
DB,

Most EC 135 are high impedance but newer Helionix aircraft are configurable so could be either. The only way to be sure on an individual aircraft is try both and see which works.

if you have an A20 already, just swap out the mic and lead for a high impedance one and see if it works.

https://www.gps.co.uk/product/bose-a...t-downleads-2/

You will also need to know which plug you need!!!

FNW


FloaterNorthWest is offline  
Old 6th Sep 2021, 17:31
  #3 (permalink)  
 
Join Date: Nov 2012
Location: UK
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Our Helionix H135 is low impedance Bose A20's, as is our EC155.

We have tried the high impedance from our AS355 and they do not work in either the 135 or 155.
Maff is offline  
Old 6th Sep 2021, 17:53
  #4 (permalink)  
 
Join Date: Apr 2010
Location: USA
Posts: 850
Likes: 0
Received 0 Likes on 0 Posts
For low impedance mic-to-high impedance aircraft, another option would be the impedance adapter from Pilot Communications USA. They have them in various connectorizations. Example: https://www.pilot-usa.com/adapters/h...rs/pa-88h.html

They also have high-to-low, which I've personally used with a DC ONE X on a UH-60, but high-to-low requires a battery and you will go through a 9V battery every day.
aa777888 is offline  
Old 7th Sep 2021, 07:50
  #5 (permalink)  
 
Join Date: Nov 2006
Location: After all, what’s more important than proving to someone on the internet that they’re wrong? - Manson
Posts: 1,841
Received 51 Likes on 36 Posts
Take a look in your Avionic Manual which is part of your maintenance documentation specific to your aircraft serial number as well as eyeballing your Audio Panels.

Pretty sure Becker DVCS which is fairly common on most models can be switched between electret and dynamic with reconfig through software.

Which way they are configured when they leave the factory seems to be connected with which way the wind is blowing on that day!!

Be aware that I think with a "dynamic" version of the A20 you cannot get "bluetooth" capability. Sometimes handy for phone calls - on the ground of course!!
RVDT is offline  
Old 9th Sep 2021, 06:25
  #6 (permalink)  
WLM
 
Join Date: Mar 2002
Location: 3 Degrees North
Posts: 370
Likes: 0
Received 0 Likes on 0 Posts
Strange, I used my A20 Bose in both our EC135T2 and the EC225LP without any issue?
WLM is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.