My head and lungs have been full of junk for nearly a week, and I've felt like dirt for most of the week. I've finally started to feel nearly human as of yesterday, and still about halfway there today.
The Cave City Hamfest is a week away, so I can't feel so blah for that.
Not much going on, though I did receive this week a long-awaited Vibroplex bug that I had given up for lost (it probably was lost, it was sent from Canada, apparently by dogsled). Yeah, another one of these “keys I didn't need” but couldn't pass up because of the price.
It's a 1932 Vibroplex Lightning Bug, and like most pre-WWII bugs, this one worked for a living. The base has been rather hastily refinished with a coat of what is likely enamel – right over the chips and scratches. This bug had a lot of scratches and wear on the base.
The nickel parts are all quite excellent, other than wear on the contacts. The original thumb piece (paddle) is there, but the operator removed the finger knob and replaced with with a wooden paddle shaped to match the original one. He put a spacer between the two, but together it makes for a rather nice keying knob. It doesn't look so hot, but it really has a good feel to it, partly because each paddle is “worn in” to suit finger placement. I told myself I would replace the finger piece, but I'm not so sure I will now. I've not yet put the key on the air, but its action is excellent. It has the original cloth-covered Vibroplex wedge plug and cord.
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A project I've been tinkering with lately is a conversion of an Astatic D-104 mic. This one was a junk one I picked up from eBay, and I'm going to retrofit the thing with an electret mic element and try it out on my Icom 746PRO/756PROIII.
This mic is an unamplified G stand, with the crystal mic element. I've removed it and will add a simple electret element. I'm looking at some simple preamp circuits too. I had considered adding instead a dynamic Heil MC-5 mic element, but I didn't want to spend an extra $35 on this project. Instead I considered buying a R/S dynamic mic and borrowing the dynamic mic capsule.
The electret should work ok, that's basically what they use in the handmike and the rather price SM-20 desk mic. They also have a built-in preamp, so I'll probably wind up adding one of the circuits suggested. I can grab phantom power (8 vdc) from the rig and avoid a battery. The G stand does not have the multi-pole switch, so the wiring isn't a hassle.
The guy that markets the 3898 Pecker (pulse amp tuner) also has an impedance matching circuit to add to D-104s, and I may consider that sometime though the circuit appears to fairly simple (a transister and a couple of electrolytic caps). His impedence matcher is designed for use with the original crystal mic element. I've aleady taken that out.
I bought a piece of universal PC board and trimmed it into a round shape that I am mounting the electret element to. I'm going to glue it to a piece of foam. I'm also adding an internal foam pop filter to the mic to replace the missing factory one. I wound up buying a R/S foam windscreen and then cut it apart so I have a large piece that I can glue inside the mic head.
I have several D-104 microphones in the shack, though not connected to anything. I had them stashed here and there, and finally grouped them all — turned out I have 4 of them, plus two I bought off eBay that had been converted into lamps. The junk one I'm converting makes … 5? I swear I still have one in the basement, but can't confirm that yet.
When I got into CB radio at age 11, I fell in love with the first D-104 I saw. I saw them in the ARRL handbook at the library, I saw them in 73, CQ and QST magazines. I wanted one but never was lucky enough to get one. I did have a Turner +2, a very art deco mic on its own, and a good performer.
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Speaking of microphones, have you seen the new Heil “Fin”? Wow! It's Heil's replica of the classic Turner Crystal 34X microphone of the 1950s, and I love the look. NOTE: The photo at top is the Turner 34X, the lower one with the blue grill is the Heil Fin — not much difference, eh?)
Heil has essentially copied the shape and added the Heil PR20 dynamic mic element. The mic also features blue LED lighting inside the mic, which lights up the blue windscreen for what has to be a very unique feature!
I've been a fan of the Turner 34X, but the only problem I had was that the mic really wasn't ideal for mounting on a boom. Neither is the Heil Fin. I'm only tinkering now with the D-104 for use as a desk mic, I don't believe I would lay down big money for a mic that looked best on the desk. I like the Fin, but I'm not looking for another accessory to clutter my rapidly disappearing work space on the shack desk. I've got enough bugs for that, don't need to add more mics.
On the microphone front, I did pick up a new classic mic for my collection, an Electro Voice 950 Dynamic mic. It's the a sorta spherical mic in shape with slots in it, not quite as stylish and the Shure 55, but certainly as cool. I haven't check the mic out for function yet, but its supposed to work (yeah, famous last words!).
I have an uncompleted revision of a classic Shure 55 that I was going to install a Heil HC-5 in, but I let that project slide after I found that a near mint 55S I picked up later actually worked well with my Icom 746PRO and Icom IC-756PROIII. I've been very happy with the mic's performance, particularly on the PROIII, which has more mic EQ provisions that the 746. It may not be as slick as the big dollar ESSB audio outfits, but its a measure of retro-ness I can afford.
I have two Heil booms setup now in the shack, one on the main desk with the 55S on it, and the other on th e left shack desk with the EV 950D. There are two transceivers among the gear on the left table, my Tempo 2020 station and then there's a Swan 350 too. The Shure 444 that came with the Swan works great, and I've never tried any other mic with it. I have so much junk on the desktop in front of the rigs on this table there's no operating space anyway! I did locate a factory Tempo desk mic to run with the Tempo, though I've never put the appropriate 4 pin plug on it (note to self, stock up on mic connectors).
One of the D-104s I have probably is wired to fit Ironsides, my Hallicrafters SR-150. Seems to me one of them was, but I may be thinking of my Heathkit SB-102. I had a D-104 on my Swan 250 that's still in the basement. That's a rig I need to keep handy for the new sunspot cycle, that baby would put out the RF.
Enough microphone talk, as it is, I need to USE them instead of blogging about them. Perhaps I'll be the first to wire a D-104 to a Yaesu FT-2000! Nah, I suspect that's been done long ago.
73 es cul … de KY4Z … dit dit