My Shure 55SW Adventure

[AE1PT]

"Experience is what you get when you don't get what you want."

And its corollary:

"Most of what we want we don't need--most of what we need we don't want."

I have come to the conclusion that very little of what I buy second hand for ham gear will be 'as advertised' or functional when I get it home. It does not seem to matter whether I use FleaBay, the fora with classifieds, or find a treasure at a hamfester. Its appearance is not an indicator of its functionality either--as I opt for the better looking junk.

HOWEVER--each and every piece ends up being a wonderful bench experience in repair, rehab, and reuse. I have come to the conclusion that if something is perfect coming in the door there is little fun to be had.

The newest case in point is my 'new' Shure 55SW dynamic mic garnered from FleaBay. The world has gone completely nuts. Anything over 20 years old is now called "vintage", and is a 'rare' 'classic'. This is of course populist marketing to drive the price of some old and common piece of shit up through the roof... The trouble with any of the 55x series of mics is that they have been inexorably linked with Elvis Presley. All flavors--from the 1939 'Fatboy' all the way to the current 55SH II are called the "Elvis Mike." Somehow this commands unreasonable prices for a very common PA and BCB service microphone.

So I scored my latest treasure at $115 shipped. I knew that the foam was disintegrated rubbish--obvious from the pics. What the seller failed to disclose was that the cartridge rattled around inside the housing like a liberal's brain at a budget meeting.

But wait! Why do I think I need the damned thing in the first place? It all has to do with this aye-yem ballbuster station that is being put together with the Valiant. 55SW into a Samson C-Valve pre, fed to a 2 channel Macintosh (vintage & classic) EQ mixer, and finally at line into a RS MPA-80 80 watt amp. Then through a bit of iron (220V to 12V filament transformer) direct to the modulator plates! Can you hear me now? :cool2:

Disassembly revealed the ugly truth. The rubber shock mounts had DISSOLVED into nothingness--except for trails of black hardened gunk. Chemical outgassing corroded solder points--along with several screws that twisted off on removal. And BS rubbish everywhere from the foam pop screen. Time to clean and test.

The cartridge was hooked to the scope (along with the spectrum analyzer). Fired up the HP 202C into a Kenwood home theater speaker. Started tracking points along the factory spec curve. Yowza! Cart was good, and within specs. The cleanup began.

Next was the reconstruction of the rubber mounts. A 2" neoprene fender washer provided the goods necessary. Sections were cut to fit the mounting recesses, and glued with black silicone. While that is drying, a full cleanup of the housing and other components was done. This is where it gets interesting and expensive. New foam pop and stand mounting hardware was gotten from Full Compass. A sheet of stainless steel screen from NAPA. MC2M (Amphenol) connectors now made by Cooper from Allied Electronics. Beer by Southern Tier Brewing Company (IPA).

Whatta mess, and what fun! I still need to bore out the screws that wrung out. Somehow the project bought a new set of Channel Lock 440 & 420 pliers (don't ask...).

Photos to follow later...

[KC2UGV]

Sounds like a pretty easy restore, since all you had to end up replacing were gaskets and pop screen. You lucked out :)

[KG4CGC]

At least you have equipment and know how. My first hamfest purchase was a giant lie. Years later after discovering the fix and seeing that it was far above my pay grade, I sold it at a substantial loss stating up front it was defective and I even included the parts.
Icom 271A. Plastic trimmer caps under the RF shield. Rushing water sound. The alignment was the issue for me.
I was a simple fix for a certain Island member.

[AE1PT]

At least you have equipment and know how. My first hamfest purchase was a giant lie. Years later after discovering the fix and seeing that it was far above my pay grade, I sold it at a substantial loss stating up front it was defective and I even included the parts.
Icom 271A. Plastic trimmer caps under the RF shield. Rushing water sound. The alignment was the issue for me.
I was a simple fix for a certain Island member.

Yup, a notorious Icom service issue. For whatever reason, they decided to pot these VCO trimmers inside the RF shield with something very much like beeswax. After a time, the wax would melt and infiltrate the trimmers.

It took about a year after I had my 751A for this to start up. Beyond your pay grade? Surely not! I bought a shitload of trimmers from Mouser and after degunking the wax replaced all of them. VCO alignment is an easy task if you have a VTVM. Every ham should have one--if just to make for bench dressing! It's surprising what one can figure out to do with one as time goes by.

I have concluded that most hamfester purchases are a giant lie. They all depend upon the final price. And always get the call of the seller. After the purchase is concluded make sure that you look them in the eye and tell them that you will be sure to visit them if something is wrong.

I had a seller hand me back $20 on an SB-610 after I said that once. Guess it all depends on how crazy you look...

[KG4CGC]

I am always up front if there is a defect issue. Large or small. All my radios smell of various tobacco smoke. Do I blow it inside? Of course not but particulates do what particulates do. Of the times I've stopped smoking and spent time in a ''clean'' environment, upon returning to a smokey home or vehicle, you reap the the stink that which you have sown.

[KC2UGV]

I am always up front if there is a defect issue. Large or small. All my radios smell of various tobacco smoke. Do I blow it inside? Of course not but particulates do what particulates do. Of the times I've stopped smoking and spent time in a ''clean'' environment, upon returning to a smokey home or vehicle, you reap the the stink that which you have sown.

I spent the past year doing that.

I pulled out a jacket from last year at the start of the winter, and it reaked of cigarette smoke. I haven't smoked in over a year now!

[kb2vxa]

Purchase price wise $115 is a bargain considering the average Fleabay price is $150+ but what's inside the housing makes for a refurbishing nightmare. Yeah, they call it Fat Elvis as a selling point but anybody of that vintage having ever seen a rock and roll stage performance knows darn well those PA mics were used by every rocker under the sun. Speaking of fat, they could call it the Big Bopper for two reasons, he used it and it can give your head a nasty lump without being damaged. BTW if you knew how to trick out a Valiant you wouldn't need all that hi-fi stuff. (;->)

Speaking of Shure, for recording it's my 330 ribbon mic and back in the daze of Radio Unmanageable aka super-fi CB it was my AGK D7. You can be sure with a Shure.

[AE1PT]

Purchase price wise $115 is a bargain considering the average Fleabay price is $150+ but what's inside the housing makes for a refurbishing nightmare. Yeah, they call it Fat Elvis as a selling point but anybody of that vintage having ever seen a rock and roll stage performance knows darn well those PA mics were used by every rocker under the sun. Speaking of fat, they could call it the Big Bopper for two reasons, he used it and it can give your head a nasty lump without being damaged. BTW if you knew how to trick out a Valiant you wouldn't need all that hi-fi stuff. (;->)

Speaking of Shure, for recording it's my 330 ribbon mic and back in the daze of Radio Unmanageable aka super-fi CB it was my AGK D7. You can be sure with a Shure.

The big bopper all right. Dropped one on my foot once and broke a toe. Not much one can do with a broken toe except hobble around with no shoe on for a few weeks. No damage to the mic...

The 55x series of mic were perhaps the most popular PA and general stage mic ever made. They could call it the JFK mic, or any one of ten thousand major and minor luminaries that stood behind one since 1939. It was that damned Elvis stamp that did the deed--and the mic shown is not even a proper representation of a Shure 55 series anything. Look at the housing openings at the top... By virtue of how common they are none should sell for more than $50-60 in good condition. Damn the postal service.

Per the Valiant (and other rigs), I will quite likely also drive it directly with the mic through the Hi-Z input. I have an W2IHY iBox on the way that will let me couple it to about anything and have PTT or VOX. The EQ is a handy thing--as it can shape down a mic performance curve to fit handily into into whatever existing SSB or AM bandwidth is available. I can sort of do that with the preamp also, but not as well.

I also believe that for any large dynamic mic the preamp and elevation to line level (then attenuation to whatever input levels are necessary) certainly makes for a solid performing package with 'punch', and avoids the rubbish that happens when one tries to amplify a weak line signal way down the wire inside a rig. Give a rig a full signal at the right impedance and good reports always follow. And that ain't eSSB or HiFi voodoo bullshit!

The amplifier trick with the Valiant is an old and respected mod. Johnson went a bit light on the iron in the modulation stage of the Valiant. Still it did just fine before I started the rehab with a stock D-104 crystal element, or the DN-HZ head. Just something to experiment with...

[NQ6U]

The big bopper all right. Dropped one on my foot once and broke a toe.

The Electrovoice 664 I use with the Drake 4-series is like that; that mic feels like it weighs twenty pounds. On the positive side, if anyone were to attack me while I was in my shack, I could use the sucker to defend myself.

[kb2vxa]

The EV-664 PA mic was very popular with hams and it matches Collins equipment perfectly aside from looking cool in front of it on the desk. The classic Astatic D-104 has an interesting characteristic published by the manufacturer that hams picked up on. When the load impedance is 50K it has a limited frequency response in the voice range 300Hz-3KHz with a presence rise making it ideal for punchy voice communications. Boat anchors typically have a 47K load provided by the grid resistor in the 1st audio stage. Raise it to 11-15M and the frequency range broadens and flattens for hy-fwy yawdio if the speech amp and driver chain has been appropriately modified. The weak link is the modulator driver transformer having DC bias from feeding the driver plate through the primary. Disconnect the winding and replace it with a 10K 5W resistor, ground the bottom end of the winding and couple driver audio to the top end through a 2uF 600VDC capacitor. Removing the bias raises the La or primary inductance lowering the bottom end from 250Hz to 40Hz. The mod iron is good to go to begin with.

"The big bopper all right. Dropped one on my foot once and broke a toe."
I feel your pain, once upon a time I dropped a chunk of concrete on my foot and did a Dr. Smith (Lost In Space TV series) for several days.

RCA made some really cool ribbon mics like the classic BK77DX "Contac capsule" and the classic 44BX diamond used on stage and in studios by vocalists in the 30s, 40s and 50s. The style was copied by Bob Heil with his Pro Line and a callsign flag copied from a radio station flag is available for that old time broadcast look.

"Per the Valiant (and other rigs), I will quite likely also drive it directly with the mic through the Hi-Z input."
That'll work, my AGK is low impedance balanced output but I got around that easily. I had it on a Shure PTT grip stand from the classic Radar O'Riley mic (don't recall the model number) and there's enough room in the neck behind the leaf switch to mount a UTC 0-1 Ouncer shielded grid input transformer. I used a standard 4 conductor shielded cord and a 1/4" 3 conductor phone plug with a matching jack on the transmitter. I couldn't find a picture of the complete stand but here are the base and PTT switch separately. Since the AM Gangstas use some pretty sophisticated equipment they often use an EQ to narrow the bandwidth when the window is crowded and expand to full fidelity when it's not. Many go full bore with a processor rack, the heart of which is a broadcast peak limiter with the Orban AM Optimod being what they drool for.

I may have mentioned I modified a Valiant bypassing the speech amp and feeding 600 ohm balanced line level audio from the broadcast processor rack to a matching transformer and through the clipper pot as a variable attenuator into the driver grid. At first I tried driving the modulator grids directly from the hi-Z center tapped secondary but couldn't reach 100% modulation without a nasty slant on positive peaks, the limiter output pushed to the max just couldn't cut the muster. Well, a little less limiter output and some driver gain and problem solved. Oh, since the transmitter doesn't load the same on all frequencies I couldn't use a fixed attenuator so I made it variable and tweaked it while watching for carrier pinch on the monitor scope. No ham should be without one to insure a clean well modulated signal without over modulation or flat topping distortion on SSB, splatter you DON'T need.

"Johnson went a bit light on the iron in the modulation stage of the Valiant."
As I said the driver transformer is the weak link and how to fix it. The mod iron is just fine for ICAS operation but won't hold up under CCS conditions. Some years ago when pirate radio was king a friend used a Valiant for a transmitter with the 160M grid and plate tanks padded down and rather quickly the transformer heated badly and the wax ran out. He came up with a "redneck engineering" solution, he took the case off and set a fan blowing across the chassis. The transformer held up but the 866s didn't like it much, the mercury condensed on the fan side of the tubes and miraculously they didn't flash over. Oh BTW his air name was Uncle Ernie and his theme song was that classic Tommy's Holiday Camp cut from the Who Tommy album. Fiddle about? (;->)

"Still it did just fine before I started the rehab with a stock D-104 crystal element, or the DN-HZ head."
Don't you mean the 10-DA dynamic head? Go for the D-104 with an 11M load and you'll sound like you've got a broadcast mic on it. I remember one of the Gangstas on 3885 who had a high power transmitter in his basement shack and footfalls on the floor above tripped the overload relay putting him off the air until he reset it. He didn't like that very much so he put a low frequency cutoff filter in it to eliminate sub-sonics. Now when you want to narrow the bandwidth just swap the 10-DA for the D-104 and you won't disturb the neighbors when they're around.

"And that ain't eSSB or HiFi voodoo bullshit!"
If it's not hi-fi voodoo bullshit it's not Angel Music but that nasty telephonium yellowy audio. On the other hand what is bullshit is eSSB that makes the audio sound too bassy, difficult to tune in properly and rather strange sounding, the worst part is it drives the neighbors nuts. I remember that BS on 20M with a few talking locally to each other in North Jersey (Bergen County if I remember correctly) better accomplished with 2M HTs. They'd spend all their time tweaking and trying to outdo each other until a spate of complaints to the FCC brought them down, thankfully. If you're going to break the rules by exceeding bandwidth limits don't use your callsign, it makes it too easy for the FCC or somebody with blood in his eyes to find you. (;->)