The tiny label on the microphone told me it was an MD421HN and the papers in the box told me it was made by Sennheiser. Time for a bit of research.
|The microphone with german product leaflet
In the box there was an original product information leaflet and a separate leaflet showing accessories (both in German). There was also this intriguing little piece of paper showing - I reckon - the frequency response of this particular microphone.
|Serial number, frequency response and production date: May 12, 1965
So.. what does one do with a 50 years old good quality microphone..
I am not much of a singer.. but maybe I can use it on my radio?
Googling a bit further I found that indeed people use this microphone on their radio set and with good results. Someone remarked it was a large improvement over the Heil headsets.
I have been using the Heil Elite Pro headset with HC-6 element for a long time now and I am more than pleased. There was absolutely no reason whatsoever to change this setup.. except for the appearance of the MD421.
I contacted a few HAMs that had mentioned using the MD421 here and there to figure out how they hooked this microphone up. With the information I got I decided to try and hook it up directly to my ICOM 756 Pro3, using the Heil plug.
Yesterday I was able to complete a cable and perform the first few tests. It seems to work. Comparing the audio via the monitor I have found that the microphone needs more drive than the Heil but it seems that with the volume on the set at 100% there is enough audio.
There was no time to do on the air tests but I did log two WWFF activators - so people seem to be able to hear me.
The microphone has two settings ("music" and "speech") and the set has various settings as well, so I will need to experiment some more and then compare the results to the Heil mic.
Whatever the outcome, it is great to put my grandfather's microphone to use again.
|My grandfather behind his piano