D104 UG8 non amplified info

[Tokin]

So i bought what looks like a nib vintage D104 UG8 non amplified with its original packaging and paperwork from Bens CB accessories 95 Shreve Street MT. Holly NJ with a telephone number of AM7-0432 lol.
I figured id share the original info as it may help someone in the future.
This mic is absolutely spotless and never used with original cord and the Astatic tie wrap still on it.

 

[543_Dallas]

Too cool. Hopefully it's been cool and dry all of these years. Good D104 elements are a rare bird.

 

[Tokin]

Too cool. Hopefully it's been cool and dry all of these years. Good D104 elements are a rare bird.

This one is pristine but im not going to use it. It will get stored in climate controlled conditions. Im playing around with an old head and different elements till i find the one like. I have a cheapo cobra ca73 element in there right now and im told it sounds good.

 

[543_Dallas]

This one is pristine but im not going to use it. It will get stored in climate controlled conditions. Im playing around with an old head and different elements till i find the one like. I have a cheapo cobra ca73 element in there right now and im told it sounds good.

The unamplified d104 will probably sound bad with a modern rig with 600 ohm impedance. They sound very good when working into a high impedance. The amp board was the solution to mate a high z element to a low Z load. You can find some audio clips of K4KYV on YouTube. The man knows how to use a d104.

 

[nomadradio]

We built a prototype batch of impedance step-down converter boards in the late 90s. The idea was to install it in a solid-state base radio so it would work with a straight D104. Kept getting asked for it by high-power operators who liked the sound of the D104 but couldn't make the amplified version behave. They said "the straight D104 never squeals on my Browning. Why won't it work on my Cobra 2000?"

A single junction FET transistor was all it took. The circuit is called a 'source follower'. The input impedance was set at 500k, with RF chokes, beads and bypass caps to keep out pesky RF. The output voltage of the D104 element is a lot higher than the low-Z mike the radio's built for. The FET only increased the current available, didn't change the audio voltage. Turned the straight D104 into a power mike without adding any voltage gain.

About the time I got ready to make it into a product, Astatic discontinued the cartridge. Made our little toy obsolete.

73

 

[Tokin]

So am i reading this wrong? This says i can rewire for low impedance.

 

[543_Dallas]

I'm not sure but I think that's just to connect the mic to a balanced input. Without a transformer or some kind of buffer you still have a high impedance microphone. Maybe what they considered low impedance back in the day is much different today. The mic I use is 150 ohms.

 

[nomadradio]

A low-impedance head gets you a low-impedance mike. The round head is always high-Z. The low-Z heads have the 'bullet' shape.

73

 

[Tokin]

A low-impedance head gets you a low-impedance mike. The round head is always high-Z. The low-Z heads have the 'bullet' shape.

73

So the dn50, 10d and 10c heads will be low z, correct?
Is there any preference?

 

[Tokin]

So im seeing the Astatic problems.
Buying used is a crap shoot.
The dn series all look the same but they aren't. There is a dn500, dn200 and a dn50 which all look the same. The dn500 is the hi z model with a transformer sealed in wax in back of the element with the 200 and 50 low z.
I haven't fully researched the 10d or 10c models yet. The ceramic 10c may be my best choice.

 

[sunbulls]

So i bought what looks like a nib vintage D104 UG8 non amplified with its original packaging and paperwork from Bens CB accessories 95 Shreve Street MT. Holly NJ with a telephone number of AM7-0432 lol.
I figured id share the original info as it may help someone in the future.
This mic is absolutely spotless and never used with original cord and the Astatic tie wrap still on it.

Use this as a replacement for yours that that looks like the Silverfish had a feast. This is probably be an older version (C1948). Many tube schematics back in those days didn't include the circle around the tube elements. It also has A little more info about those three main tube applications, Conventional, Transformer Coupling, and Push Pull.

 

[Tokin]

So i have successfully transplanted a dynamic mic element from a pos cobra ca73 microphone into a d104 head. The pos part of that mic is the ptt which is plastic on metal so it creaks a lot. I found a secret item for the baffle. Its a 3"x1/2" neoprene clone box insert.

 

[543_Dallas]

So i have successfully transplanted a dynamic mic element from a pos cobra ca73 microphone into a d104 head. The pos part of that mic is the ptt which is plastic on metal so it creaks a lot. I found a secret item for the baffle. Its a 3"x1/2" neoprene clone box insert. View attachment 39809

Take care of that old element. If it's good someone with a vintage transmitter would love to have it.

 

[Tokin]

Take care of that old element. If it's good someone with a vintage transmitter would love to have it.

I used an extra head for the experiment so the new head was put back in its original protective thick ass paper bag and is being climate controlled stored.

 

[Czar]

Good afternoon, folks. Brand-new guy here, Technician Class exam this afternoon.
I've got a similar question about the unamplified version of the D-104, which I purchased about 8 years ago when I got my FT 857D (I was pretty slow about getting started

I'd LIKE to use the TUG 8/D-104 for normal operations, but I hear there are some issues with the old crystal mic's compatibility with modern radios that I don't fully understand. I've pictured a pigtail that could be potentially wired onto the TUG-8 and then be plugged into the Yeasu. I'd loose the channel up/down/fast feature that the MH31 hand mic has, but for now that would be OK.

Alternatively, what about taking the guts out of the MH31 and adapting them to the Astatic platform? Has that been attempted? I did see a reference to the MH31 mic that was pretty unflattering, that it was just garbage.

I build guitars full time now that I'm retired, and am handy with soldering stuff up, and am not afraid of digging in. BUT, my understanding of electronics is fairly limited.

Looking forward to hopefully being a productive member of the boards here. Thx for having me. - John