The SB40 has a dynamic microphone, so the usual K3 settings for that are High Gain / No Bias.

If you are running the SB40 into a sound card, you need a card with 20dB boost on the microphone input.

One SB40 reviewer tried to replace the dynamic element with an electret, but he said there was insufficient lead length left after he removed the dynamic element.

As a last resort, you can tape pretty much any old electret element to the mic boom and run a separate mic line from the element. Mouser has a good selection of electret elements, many under $5. My CM500 microphone element failed, and I replaced it with an electret element out of an old toy that I found laying around the house. It sounds fine.

The SB45 headset has an electret element, but it is not the same comfortable headphone arrangement as the CM-500.

Dave Hachadorian, K6LL
Yuma, AZ


-----Original Message----- From: [email protected]
Sent: Thursday, November 5, 2015 6:40 PM
To: [email protected]
Subject: [Elecraft] K3 Yamaha CM500 vs Koss SB40


My CM500 was looking kinda 'ratty' after 4 yrs with ear cushions
starting to shed material. Saw where someone said that Koss actually
makes the CM500 for Yamaha so ordered the SB40 as replacement.

First trial was CQ WW SSB a couple of weekends ago.  Rig had been
sitting in the closet for several months so brought it out and coupled with Buddipole, 6ft out the window of 24th floor apartment here in HP.
Audio reports were terrible including those from guys who knew my
voice...I had to 'close talk' the SB40 with mic touching lips....using VOX as could not find the foot switch adaptor for the Heil footswitch. Vox had never been an issue as I have used VOX on the K3 for 7 years with no issues...best Vox I have ever experienced....audio was so bad, one guy suggested to turn down the drive on my amp....I was running
barefoot K3/100 @ 90w.  Found CM500 in packing box and got it
going....audio became the usual outstanding.

So, what is the difference between these two headsets and what can I do
to properly use the SB40?

BTW, the Buddipole/CM500/K3 combo was great...due to proximity to
building, could only use BP on 10 and 15m...worked over 600Qs in 3 hours
on 10m on Sunday pm......great fun.

Suggestions for using the SB40 w/K3?

73 Tom HP1/K6CT aka CX7TT
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]

Reply via email to