Using Ceramic / Crystal Mics on New Radios

<< < (2/4) > >>

WD4DMZ:
Good afternoon. I'm currently using un-amplified crystal D104s on my Viking 2 and Collins KWM2 with good reports. No issue here.

I also have a few amplified D104s and questions for the experts:

1- What is the output impedance of these? Low? High (10,000+ ohms)?

2- Would the amplified version be ok to use on the V2 or KWM2?

3- Would they be ok to use on modern radios?

My concern is over-driving the audio input circuits.

Any advice would be appreciated.

Rich

MikeKE0ZUinkcmo:
Hi Rich,

The output node of these amplified mics is the wiper of a 5K Ohm pot, so the output resistance will be at most around 5K.   

The original purpose of the "amplifier" was to  allow the Hi-Z mics to be used with the low input impedance of CB radios, so they were intended as an impedance converter.   I never measured one of the amplified mics to see what the maximum output level is, but it should be sufficient to still use on old gear as well as modern radios.   In any even t I'd think most any rig would have some sort of mic gain control, and over driving shouldn't be a problem.

Mike

DMOD:
Stu has some interesting results from an experiment:

http://amfone.net/Amforum/index.php?topic=9100.0


Phil - AC0OB

WD4DMZ:
Thanks for the info Phil. Great data.

Back around 2010 I ordered two of the Kobitone crystal elements referenced in the thread to use in a bad D104 head and to make a handheld mic for my Collins. They were very inexpensive and worked great.

Unfortunately the elements are no longer made. I wish that I had purchased a few more. Does anyone know of available Hi-Z elements to use as replacements? Nothing at all at Mouser any more.

Thanks, Rich

WA2SQQ:
So I have another question. I'm using my original Crystal D-104 with an MPF-102 interface feeding my Flex 6500. It works fine. I also have one of the newer amplified "Silver Eagles". Does that version use a crystal element or the often mentioned ceramic element? Is there any way to visually tell them apart?

Been playing around with alternate mics. I found a new "crystal" element made by Argonne that Lafayette sold for .99 cents, along with the receipt when I purchased it in 1968. It sounds remarkably close to the crystal D-104. To bad I did not more! I've been tod that this was the same element used in the "Green Hornet" mic Lafayette sold for $4.95

Navigation

[0] Message Index

[#] Next page

[*] Previous page