swallows Posted November 16, 2020 Share Posted November 16, 2020 Hello, I have a query for canadian Labradors experts. I'm putting the finishing touches to a model of the CH-113 in its initial delivery colors and I got curious about the strange aerials just behind the cockpit. Those on the left are simmetrical and can be seen in the first few years of service (late '60s - early '70s) while the strange plate came later and I think is only on the left side (on the right there would be the cabin door in the same position). The first set is already identified being a common set for SAR duties in the early years, though the one on the right is quite obscure. Anybody knows what it is and how it worked? Again speaking about details, what is that black vent(?) in the rear pilon? No other V-107 incarnation has it and it disappeared together with the above aerials when the fleet was upgraded and repainted in yellow in 1981. Thanks a lot for any reply! Fabio Quote Link to post Share on other sites
Tank Posted November 16, 2020 Share Posted November 16, 2020 (edited) I wonder if the second photo is an antenna similar to what was used on the UH-34. Maybe a way for Canadian SAR to communicate with US forces??? Edited November 16, 2020 by Tank Quote Link to post Share on other sites
Da SWO Posted November 16, 2020 Share Posted November 16, 2020 I'll guess they are a direction finding receiver of some type. Allowing the crew to "home" in on a distress beacon, radio. Quote Link to post Share on other sites
JohnEB Posted November 17, 2020 Share Posted November 17, 2020 The first photo looks like FM antennas to me. Quote Link to post Share on other sites
swallows Posted November 17, 2020 Author Share Posted November 17, 2020 Thank you for your contributions, they stimulated further research and I drew the following conclusions based on observation of images and snippets of info found here and there: the first image is for the SARAH system receiver. As suggested by @Da SWO it was a direction finding device used to locate the target during SAR missions. It was later replaced by a set of whip aerials under the belly. The second image depicts an HF aerial for long distance communications. It is completely unrelated to the first one, it replaced the initial long wire aerial on the left side and after a short spell the third incarnation was the 'towel rail' aerial so characteristic of the Labrador and Voyageur. Just when I was doing the umpteenth google search I found this page were everything is very well explained in word and pictures: http://cdnsarlab.blogspot.com/2012/02/operational-differences-antennae.html?_sm_au_=iVVnM4FMP2RkHZqdK82BvK0JskMpq Well, at least I was not wrong 🙄 Now there is still that black vent in the rear pilon. I checked hundreds of images but it seem a peculiarity of just the early Labrador, no other V-107 has it. Really strange! Quote Link to post Share on other sites
yahya Posted May 21 Share Posted May 21 Do you happen to know the type of the High Frequency radio set used on the early CH-113s? Below is a sketch from the manual from the 1960s. While other avionics pieces can be easily identified, the HF radio remains a mystery. Notably, the control panel has separate knobs to choose one from ten transmitter and ten receiver preset frequencies. Quote Link to post Share on other sites
Winnie Posted May 30 Share Posted May 30 Duplex HF, send on one, receive on another. It makes for clearer transmission. Obviously you'd have to agree which channel to transmit and receive on. I was a naval communications office in my youth and we used DUPLEX HF to patch long range phone calls amongst others. That they had the capability doesn't mean they used it often. HF is not a great system to communicate with in general... and depending on what you were sending , such as voice, or morse (CW) or teletype, would dictate where in the sidelobe of the signal you'd listen... 2hz, 0hz or 1.5hz off of the frequency... shudder.. Quote Link to post Share on other sites
andyf117 Posted June 1 Share Posted June 1 On 5/30/2024 at 10:12 PM, Dutch said: Good info, eh! Always good to learn more aboot Canadian Labs... Quote Link to post Share on other sites
yahya Posted June 6 Share Posted June 6 On 5/30/2024 at 3:01 PM, Winnie said: Duplex HF, send on one, receive on another. It makes for clearer transmission. Obviously you'd have to agree which channel to transmit and receive on. I was a naval communications office in my youth and we used DUPLEX HF to patch long range phone calls amongst others. That they had the capability doesn't mean they used it often. HF is not a great system to communicate with in general... and depending on what you were sending , such as voice, or morse (CW) or teletype, would dictate where in the sidelobe of the signal you'd listen... 2hz, 0hz or 1.5hz off of the frequency... shudder.. Do you happen to remember the radio set as used on the CH-113? Meanwhile I established that it was made by the Canadian Marconi Company (CMC). The manufacturer unfortunately was not able to help as far as the nomenclature and specs of the radio are concerned. I presume that the radio supported AM (voice) and CW (telegraphy), and not SSB (single sideband voice). Quote Link to post Share on other sites
Winnie Posted June 7 Share Posted June 7 No, sorry. I was a sailor, in Norway... I just was a teletype and CW specialist. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.