[Elecraft] Microphone for K2

[redmen1969 at optonline.net]

I had the occassion to take apart the hand held mic that Elecraft carries (MH-2?) and was really shocked at what I found inside.

Now as a mostly CW guy I really don't have a good appreciation of sound quality, but I'm finding this thread very interesting.

Tom
WB2QDG

----- Original Message -----
From: Jim Brown <jim at audiosystemsgroup.com>
Date: Wednesday, September 1, 2004 8:22 pm
Subject: Re: [Elecraft] Microphone for K2

> I must not have been clear. it is not "another option" -- it's 
> precisely the 
> Plantronics headset I noted I had seen at Fry's Electronics. So 
> everything 
> that applies to making a cell phone headset work applies equally 
> to 
> making the PC headset work.  
> 
> The point is that these headsets differ only in 1) the quality of 
> the headset 
> and mic elements; 2) Physical comfort; 3) the connector(s) on the 
> end. All 
> of the Plantronics headsets have noise cancelling mics. Bill, 
> NY9H, has 
> observed that these capsules (and the capsules used in the VERY 
> expensive ham mics) sell for half a dollar or less without the 
> name of the 
> very expensive ham mic marketing company on them. 
> 
> Another point. Plantronics is an old line telecommunications 
> company. 
> The "Altec Lansing" NAME was purchased at least a decade ago, is 
> applied to cheap junk from the far east, and sold. There is no 
> connection 
> (other than this sale of the name) between the company using the 
> name 
> and the company that MADE the name a household word for high 
> quality 
> audio. In spite of its pedigree, I'll bet your headset works a 
> treat on the K2!  
> 
> What can be very tricky to get to work is a headset with an inline 
> PTT 
> switch sold to work with a ham talkie. In essence, you have to do 
> major 
> surgery on what is a very delicate (and cheap) switch with very 
> tiny and 
> delicate wiring to either disable it or rewire it to work with a 
> radio for which 
> it was not intended. I  bought one of these new at a hamfest. VERY 
> bad 
> idea. 
> 
> Jim Brown  K9YC
> 
> --Original Message Text---
> From: G3VVT at aol.com
> Date: Wed, 1 Sep 2004 19:08:31 EDT
> 
> Another option may be to use a PC microphone/headset that are 
> available in the market 
> at very low prices. I use an Altec Lansing AHS-201 headset 
> electret boom microphone 
> with a single earpiece with my K2. As the headset is terminated in 
> the standard 2 x 
> 3.5mm stereo jacks I made up the necessary connectors and a PTT in 
> a small plastic 
> box with two leads out for the K2,  8 pin mic connector and a 
> 3.5mm stereo plug for the 
> headphone connector. A foot switch could be added if desired for 
> PTT. The +5V bias 
> voltage is already available at P1 on the K2 Front Panel board. 
> All it takes is a suitable 
> resistor to provide the bias voltage needed from the +5V on P1 pin 
> 6 to the designated 
> AF pin or pin 1 on the K2/KSB2 side. There is already a 2.2uF 
> isolating capacitor, C34 
> on the KSB2 I/P, so no other isolation is required with the 
> standard K2/KSB2. The bias 
> voltage needed for the Altec Lansing AHS-201 does not seem 
> critical. I used a single 
> AA 1.5V dry cell in tests and with that was able to overdrive the 
> K2 in the microphone 
> high setting.
> 
> An added advantage with this particular headset is the microphone 
> is noise cancelling 
> for use in noisy situations and the earpiece seems to work well 
> with the K2 giving a 
> good RX audio level. I had built the setup originally to use with 
> a Yaesu VHF/UHF 
> mobile and it was pleasing to find that it worked very well with 
> the K2. Trying it out was 
> easy as I already used the Yaesu standard for the K2 8 pin 
> microphone connector. The 
> Altec Lansing AHS-201 should be retailed from about $10 in the 
> USA. The obsolete 
> AHS-15 should also work well at an even cheaper price if still 
> available. 
> Bob, G3VVT
> K2 #4168
> 
> 
> 
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