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THE AM BULLETIN BOARD => Technical Forum => Topic started by: WA2SQQ on March 13, 2015, 08:37:56 AM



Title: D-104 Restoration Project
Post by: WA2SQQ on March 13, 2015, 08:37:56 AM
For anyone considering a restoration project that includes hammer tone  paint, I’d highly recommend using the Rustoleum product now being sold by Lowes and Home Depot. I decided to bring my 1950’s D-104 into the 21st century. Somewhere along the way it got sprayed with candy apple blue paint.

I used the Goo-Gone sprayable paint stripper and removed the blue and original gray hammer tome paint with one application. To my amazement, the base was almost chrome-like and I almost decided to just clear coat it. All the minor dings and scratches were corrected with a thin coat of automotive red glazing putty. After drying, the base was wet sanded with 800 grit sand paper. One light coat of the gray hammer tone, followed by another wet sanding, and finally the second coat of the hammer tone paint. This paint needs to be applied in two or more light coats as it can “puddle” very easily.

Finally, I built and installed an FET source follower circuit using an MPF-102 to bring the D-104’s extremely high impedance down to something useable by my Flex 6500. It looks great, and sounds just like it did on yesteryear’s tube transmitters. Next project will be doing the same to my Turner 254C which was also originally gray hammer tone.


Title: Re: D-104 Restoration Project
Post by: KA0HCP on March 13, 2015, 01:40:29 PM
Wow, super job.  Thanks for the encouragement.


Title: Re: D-104 Restoration Project
Post by: W3GMS on March 13, 2015, 02:29:16 PM
Looks great!  A lot of folks think the D-104 are tinny microphones and that is simply not the case but you do have to know how to interface them correctly.  Its a shame the cartridges are not made anymore. 

Similar paint works on a lot of the vintage Elmac gear.  It does a great job. 

Joe-GMS


Title: Re: D-104 Restoration Project
Post by: Tom W2ILA on March 13, 2015, 06:23:12 PM
That turned out great.  I have never seen that version of Rustoleum and will look forward to giving it a try.  There is another version of rustoleum in the more traditional can simply labeled Hammered.  It was tough to spray, too lite and it didn't hammer, too heavy and it pinholed. With practice it worked. 
Another brand is Hammerite which is getting tough to find but when you find a hardware store that carries it they usually have a bunch of colors.

Tom


Title: Re: D-104 Restoration Project
Post by: DMOD on March 13, 2015, 06:34:20 PM
Looks great!  A lot of folks think the D-104 are tinny microphones and that is simply not the case but you do have to know how to interface them correctly.  Its a shame the cartridges are not made anymore. 

Similar paint works on a lot of the vintage Elmac gear.  It does a great job. 

Joe-GMS

For sure. I need a replacement cartridge for my D-104.

Phil - AC0OB


Title: Re: D-104 Restoration Project
Post by: W2VW on March 13, 2015, 06:36:07 PM
Thanks for posting an actual D-104 restoration thread instead of some of the hackery usually seen with these mics.


Title: Re: D-104 Restoration Project
Post by: k3pf on March 14, 2015, 02:15:11 PM
I found a crystal element rebuild kit for the D-104 microphone at the Northland Drifter's site.  Go to this web address to see the order info.  http://www.rbmicro.com/


Title: Re: D-104 Restoration Project
Post by: W9BHI on March 14, 2015, 02:19:10 PM
What brand of hammertone paint did you use?

Don W9BHI


Title: Re: D-104 Restoration Project
Post by: k7iou on March 14, 2015, 06:12:40 PM
What brand of hammertone paint did you use?

Don W9BHI

RUSTOLIUM see 2nd picture in 1st post.

Or if you have your own spray gun and air compressor this is the paint that matched the WRL Globe King 500
http://www.idealtruevalue.com/store/p/169644-QT-Silver-Hammered-Finish-Self-Priming-Paint-Can-Be-Applied-Directly-O.aspx?feed=Froogle&gclid=CICb8KTFqMQCFYRufgoduG8A4g

http://www.walmart.com/ip/Masterchem-43105-1-Quart-Silver-Gray-Hammerite-Rust-Cap-Enamel-Interior-Paint/21798233

http://www.qsl.net/wa5cmi/cabinet.htm
 


Title: Re: D-104 Restoration Project
Post by: N2DTS on March 14, 2015, 10:01:44 PM
I have used the hammered finish paint on some motorcycle and car stuff and it works very well, very tough finish.
I also used it on a bunch of rusty side supports that hold the front panel to the chassis, you can paint right over light rust.
Its a great look for a d104 base.

They also make gold hammered finish.

There is also cast finish, a cast alluminum look, but its flat, looks like flat silver/grey paint and does not hold up well.


Title: Re: D-104 Restoration Project
Post by: WA2SQQ on March 16, 2015, 09:49:12 AM
A few people asked me about the source follower circuit I added.
I actually combined two circuits. The main circuit was explained at the link below.
I added the bass and treble adjustments shown in the attached photo.

http://www.qsl.net/hcara/Improving_the_D-104_N9WB_rev2.pdf


Title: Re: D-104 Restoration Project
Post by: WA2SQQ on March 16, 2015, 09:54:05 AM
What brand of hammertone paint did you use?

Don W9BHI

Rustoleum - see the photos I posted
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands