trophy160 Posted June 8, 2013 Share Posted June 8, 2013 Is it possible to use a Clansman headset with a Larkspur harness and if so what is the pin configuration. Thanks Quote Link to comment Share on other sites More sharing options...
g0ozs Posted June 8, 2013 Share Posted June 8, 2013 Hi The Larkspur and Clansman Harness boxes and cabling are described at: http://wftw.nl/harnessb/harness.html (Larkspur) and http://www.ferret-afv.org/manuals/clansman_wiring_harness_and_control_boxes_description.pdf (Clansman). I assume you want to adapt a Clansman headset to fit a C or D Box. The Clansman headset has 7 pins and the connections are at: http://www.g0ozs.org/clansman/audio.shtml The microphone impedance is around 600 ohms and the headphone impedance is around 60 ohms from memory. Larkspur headsets had a 6 pin connector. I am not sure they are all the same but the EMER for station radio A13 gives A MIC B A13HP (special to that radio) not connected on headset C PRESSEL D EARTH E BATTERY (not connected on headset) F PHONES For the radio headgear connector. This is confirmed by inspection of the Station Radio A43R circuit diagram. What I don't know is the impedance of the Larkspur headphones and microphone - if very different from Clansman you may have problems with audio levels even if correctly wired. If the A13 headgear was compatible with the harness boxes I'd expect to connect the Clansman headphones in series between Larkspur F and D, and the Clansman microphone between A and ground. You will need a PTT switch between C and ground to transmit. Probably the best thing is to make up a pressel box with a clansman socket one end and a Larkspur audio cable the other. The picture at http://www.armyradio.com/arsc/customer/product.php?productid=1452&cat=84&page=1 may also be of interest. I'm not sure it is still in stock (no price) but would have been what you needed to get intercom in the Saracen. Hope this helps Iain Quote Link to comment Share on other sites More sharing options...
g0ozs Posted June 9, 2013 Share Posted June 9, 2013 (edited) Now had a look at EMER L772 for Larkspur A harness. Para 93 gives audio socket pins on CU31 and JD8 boxes as A Audio In from Microphone B Microphone Earth C Pressel (ground to TX) D Headphone Earth E Voltage control (CU 31 Only) F Audio out to Headphone According to L772 Para 13 the microphone was 300 ohm dynamic and the headphones were 2 x 300 ohm in parallel so the radio or harness saw a load of 150 ohms. Also note that Larkspur crew boxes and commanders personal units had a volume control "Gain" which may allow some optimisation. I'd expect Clansman headgear to work OK if re-wired or connected via a home made "personal unit" in place of the Clansman pressel box. Good luck! Iain Edited June 9, 2013 by g0ozs Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 9, 2013 Author Share Posted June 9, 2013 Excellent, thank you very much for the information Ian. Quote Link to comment Share on other sites More sharing options...
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