+++++++++++++++++ From: Margaret Leber To: "Kirby J. Davis" Subject: Re: [Elecraft] David Clark headsets Date: Wed, 6 Mar 2002 00:49:28 -0500 Cc: On Tuesday 05 March 2002 22:53, Kirby J. Davis wrote: > I emailed the David Clark company to ask about the impedence of the > headset but their response didn't give me the answer. I know that I > would have to get a plug adapter. The schematics at their website say the speakers are 300 ohms. I have a pair myself that I use while flying, but I sure wouldn't want to wear them for anything else that didn't need 24dB of noise protection...like maybe target practice with a .45 cal pistol. :-) They're *heavy* and put pressure on your head to achive a good seal at the ear cups. 73 de Maggie K3XS -- -----/___. _) Margaret Stephanie Leber / "The art of progress / ----/(, /| /| http://voicenet.com/~maggie / consists of preserving/ ---/ / | / | _ _ _ ` _AOPA 925383/ order amid change and / --/ ) / |/ |_(_(_(_/_(_/__(__(/_ FN20hd / change amid order." / -/ (_/ ' K3XS .-/ .-/ ARRL 39280 /___ --A.N.Whitehead ___/ /____ICQ 7161096_(_/_(_/__AMSAT 32844____/ ++++++++++++++++++++++ From: alta Reply-To: alta at alta-research.com Organization: Alta Research To: "Kirby J. Davis" , Subject: Re: [Elecraft] David Clark headsets Date: Wed, 6 Mar 2002 08:30:48 -0800 Aviation mikes simulate a carbon mike, which requires a bias current. I do not know if the K2 supplies a bias current. With some experimentation, you should be able to get it to work. However, you will need to supply a bias current (5 ma at 6v?) and the output might be a higher level than the norm. ... Reed On Tuesday 05 March 2002 19:53, you wrote: > Would anyone know if it is possible to use a David Clark H10-30 > noise-attenuating aviation headset as a headset for the K2? I have > one of these from my private pilot days about a decade ago... no > plane and no active pilot license but I do still have the headset! > ++++++++++++++++++ From: "Stuart Rohre" To: "Kirby J. Davis" Cc: "elecraft" Subject: Re: [Elecraft] David Clark headsets Date: Wed, 6 Mar 2002 14:24:47 -0600 Most aviation audio circuits have been traditionally 600 ohm systems, so probably the Clark has two 300 ohm phones in series. You could get a 600 ohm to 8 ohm transformer from Radio Shack and use that to match the K2, close enough. Probably however, there is adequate audio in the K2 to drive the high impedance phones line directly. 72, Stuart K5KVH ++++++++++++++++++ From: alta Reply-To: alta at alta-research.com Organization: Alta Research To: "Stuart Rohre" , elecraft at mailman.qth.net Subject: Re: [Elecraft] David Clark headsets Date: Wed, 6 Mar 2002 22:41:25 -0800 Depending on the model, newer models are noise cancelling electret or dynamic. The headset contains electronic circuitry to make it "look like" a carbon mike. ... Reed On Wednesday 06 March 2002 14:15, you wrote: > Good point about the mike side of aviation sets. Better to change > out that carbon element if fitted with a good quality Heil > cartridge, or similar, even an electret element from Radio Shack. > Of course, and electret needs a voltage in most cases. > PVDF type elements may not. Dynamic mike elements from older mikes > do not need power, if they fit. > > 72, > Stuart K5KVH +++++++++++++++++++++ Subject: Re: [Elecraft] David Clark headsets Date: Thu, 7 Mar 2002 15:56:38 -0500 From: Bill Coleman To: "Kirby J. Davis" , On 3/5/02 10:53 PM, Kirby J. Davis at kb4utz at usa.net wrote: >Would anyone know if it is possible to use a David Clark H10-30 >noise-attenuating aviation headset as a headset for the K2? I'm sure it is possible, but there are certainly a lot more comfortable and compatable headsets to use. >I have >one of these from my private pilot days about a decade ago... no >plane and no active pilot license but I do still have the headset! Pilot licenses never expire -- unless you had to surrender yours.... >Any ideas or thoughts? The headset is quite nice and I would think >that it could find good use in "ham service"... seems like it would >be a waste not to try to use it. I'm pretty sure you can drive the headphones, but the microphone may be more problematic. Aviation headsets either use or simulate a carbon mike element, so you have to provide a bias voltage across the microphone leads to get them to work. Aviation headsets were designed to be used in a very noisy environment for modest periods (eg 1-4 hours). The typical hamshack isn't nearly that noisy. The tradeoff for headsets is protection over comfort. These headsets aren't very comfortable. They will hurt your head after just 5-10 minutes. However, in an aircraft, it is better than going deaf. If you trying wearing them for 10-20 hours (as in a contest), you'll definitely give yourself a head-vice headache. There are much more comfortable aviation headsets than David Clark. I'm most impressed with the Peltors. They are light, comfortable, and just as effective. I bought two of their hearing protectors (no speakers or mike, just the headset) for use in my workshop. Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr at arrl.net Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ++++++++++++++++++++