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THE AM BULLETIN BOARD => QSO => Topic started by: Steve - WB3HUZ on August 31, 2009, 09:48:02 PM



Title: Story of a Transmitter Restoration
Post by: Steve - WB3HUZ on August 31, 2009, 09:48:02 PM
W8VR has a nice story of the life of an old transmitter and its recent restoration.

http://www.w8vr.org/


Title: Re: Story of a Transmitter Restoration
Post by: Todd, KA1KAQ on August 31, 2009, 10:03:13 PM
Schweeet! That's a nice looking transmitter from the start. Good job of going through it with necessary upgrades to make it solid.

Didn't know they made hot pink HV wire. I bet Fabio and Doctor Love would appreciate such an upgrade.  ;D



Title: Re: Story of a Transmitter Restoration
Post by: W1AEX on August 31, 2009, 11:19:00 PM
The attention to detail is remarkable. The wiring underneath each chassis is incredibly precise. Very impressive piece of work!


Title: Re: Story of a Transmitter Restoration
Post by: KL7OF on September 01, 2009, 01:42:02 AM
The black wrinkle chassis look great....When a painted chassis is used, is a star washer enough to assure a good chassis ground?  The filament leads have a very tight even twist on the speech amp..Very impressive work.


Title: Re: Story of a Transmitter Restoration
Post by: WA3VJB on September 01, 2009, 05:11:30 AM

Reminds me of the construction style and quality of the tube-type Lambda power supplies.

Very cool stuff.

What struck me odd is modern photography on authentically old-looking brand new gear.

Doesn't Adobe PhotoShop have a tab that says "make photo look old"  ?



Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 01, 2009, 07:57:32 AM
To: KL7OF

Tnx OM, fer ur kind words.

I wouldn't trust a star washer to make a decent contact through a powder-coated surface, as the finish is very very tough.  Additionally, even if a tang or two of the star washer did penetrate the coating and look good on the ohmmeter, the connection might be unreliable and of higher-than-wanted impedance. 

Where I wanted a chassis connection point (there are very very few), I ground away a small circle of the powder coating with a Dremel motor and a small cylindrical grinding tool.  Consider placing the tool on one side of a chassis hole, the motor on the other with the grinding-tool shaft passing through the hole, and then grinding with the inner surface of the grinding tool while pulling on the Dremel motor.  This technique will keep the ground area reasonably concentric with the hole.

The twisted filament leads in the speech amp are but one means of reducing hum.  They are twisted evenly by fastening ends of two equal-length wires into a bench vise and putting the other ends into an electric drill chuck, the wires pulled taut, and the drill then run at low speed.

Soldering close to the wire insulation without melting it, is easy with teflon-insulated wire!

73 de al hart, w8vr


Title: Re: Story of a Transmitter Restoration
Post by: WBear2GCR on September 01, 2009, 02:45:55 PM


Two questions:

1) Are there any "before" pictures?
1.5) you said there were comparison images of the before and after wrinkle/crinkle finish?
(I'm not particulary finicky about it, but I am curious...)

2) Where, when and how did you learn to do that harness lacing??

Afaik, when mfrs did harnesses they were done using a pattern board that permits the wires to be laid out and laced, then the entire harness is placed into the gear and trimmed and soldered in place... how did you do yours?

               _-_-

PS. there is a tool that is used in machine shops - I am not sure of the proper name at the moment - but it is an end mill with a short center "pin", this permits the mill to follow a hole and mill precisely around it to some diamter. I think maybe it is a shoulder mill or shoulder cutter... one of these would  be ideal for clearing the paint or powder coat from a surface. Given its small size it would work ok in a drill press or even a steady hand with a hand drill...



Title: Re: Story of a Transmitter Restoration
Post by: W1VD on September 01, 2009, 07:05:25 PM
Quote
there is a tool that is used in machine shops - I am not sure of the proper name at the moment

'counterbore' or 'spot face'


Title: Re: Story of a Transmitter Restoration
Post by: Opcom on September 01, 2009, 07:41:40 PM
The tool that has a short center pin  the ones I have fit in rack-screw holes. The "mill" end is wire brush and they 'dust' the paint and rust right out of there so the panel and hardware makes contact well.


Title: Re: Story of a Transmitter Restoration
Post by: W3SLK on September 01, 2009, 08:17:54 PM
I checked out that speech amp. What an awesome job! Man that tying and bundling of the wiring had to be nothing short of frustrating!


Title: Re: Story of a Transmitter Restoration
Post by: W1UJR on September 01, 2009, 08:18:06 PM
Wonderful work Al, just wonderful!

The attention to detail on the mod and power supply decks are amazing,
you did a 1st class job bringing that rig back from the edge.

Great write up on powder coating by the way, I had the same
conclusions. In fact had a nice talk at the AWA Conference last month
with on OT, W3DGB, about the wrinkle painting process. Your friend's
powder coating work looks wonderful, and that finish will outlast all
of us!

A quick question on the powder coating of the xformers.
Did you coat just the end bells, or the laminations as well?
I've run into that before, but was told the powder coat temps are
not good to subject the complete xformer too, wonder how you
got around that?

Didn't see any images of the finished final deck, but
wonder if the rig on the air yet?

Can you tell us a bit about its background and history?

Your image files were amazing, I'd be curious how you shoot those,
first class pro level work. I noticed no background images, can
you share how you shoot those?
I'd doing a restoration of a 1937 Lafayette rack transmitter,
and would like to have my photo documentary look as nice as yours.

I don't think we'd had the pleasure to work on air, but
hope that add my station to your list for the maiden voyage
of this rig.  :D

Tnx,
Bruce W1UJR
www.W1UJR.net


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 01, 2009, 11:25:28 PM
Everyone:

Thank you all for your kind words - I appreciate each and every one of them.

Let me try to answer several posters' questions in this one reply:

1.   Are there any “before” pictures?

   Only those posted on the website.  I have none of the speech amp, but the other stages show both “before” and “after” pictures.


2.   Where, when, and how, did you learn to do that harness lacing?

   In 1953-1956, I was an electronics tech at Armour Research Foundation in Chicago.  We built experimental gear for the gov’t and we had to make it not only physically and electrically reliable, but it had to look nice.

   Yes, I used one small "cable board."  I used it for some of the behind-the-panel wiring of the final amp power supply, but it’s not visible in the pictures.  I’ll also use a big one, 2' x 8', for the two inter-deck cables, which I’ll be working on in about a month and a half, or so.  I'll photograph that process.  Much of the BigRig cable-lacing was done in situ, without using cable boards.  While one must take care to use the correct knots, lacing is an easily learnable albeit time-consuming process and I’ve seen instructions on the web.


3.   Did you coat just the end bells, or the laminations as well?

   My powder coater uses a temperature of 400 deg. F., so complete transformers cannot be safely powder coated.  Where the end bells were removable, I painted a couple and had the rest powder coated.  Where the end bells were not removable, I painted them, drying them in my home-built painting oven.  In all cases, I painted the laminations with 3 coats of black satin paint.


4.   Is the rig on the air yet?

   The final amplifier is not yet completed, so the rig has not been on the air. In fact, only today did I strip down the old final, so it’s restoration is now underway.  Take a look in my “Sundry Stuff” folder on www.w8vr.org, and you’ll see a photo of the 7 decks done so far, but not yet mounted in the rack.  I'm hoping to have it on the air for initial testing, somewhere around the first of the year.



5.   How were the pictures made?

   The pictures were shot with a digital camera, the subjects illuminated by bare-bulb flash reflected from the ceiling, with a second smaller flash as a fill-light.   The white backgrounds were done in Photoshop.


6.   Can you tell us a bit about its background and history?

   I’ve tried to do that in detail, on the website at www.w8vr.org.  On the homepage, click on the mike, and you'll be taken to a lot of relevant text.


73 de al hart, w8vr.


Title: Re: Story of a Transmitter Restoration
Post by: W2XR on September 02, 2009, 06:46:36 AM
Beautiful workmanship and attention to detail!

I have always said the quality in any restoration or homebrew project is in the sum of the details.

Great website, too!

We all look forward to hearing that rig on the air.

73,

Bruce


Title: Re: Story of a Transmitter Restoration
Post by: WBear2GCR on September 02, 2009, 10:49:38 AM
Quote
there is a tool that is used in machine shops - I am not sure of the proper name at the moment

'counterbore' or 'spot face'

Right! CRS strikes again...

The pins are available in various diameters for a given mill diameter...

I've never seen a wire brush version Patrick! Maybe you can post a link to a supplier or a jpeg of the actual thing.

                         _-_-bear


Title: Re: Story of a Transmitter Restoration
Post by: WA1GFZ on September 02, 2009, 12:21:28 PM
looks like mil work! Beautiful


Title: Re: Story of a Transmitter Restoration
Post by: W7TFO on September 02, 2009, 04:35:48 PM
Mucho Kudos! 8)


Title: Re: Story of a Transmitter Restoration
Post by: Opcom on September 02, 2009, 11:37:41 PM
Pilot Bonding Brushes are specially designed to clean around rivet or bolt holes. Brush diameter is ½"; Trim length is 3/8"; Brush is filled with .004" Stainless Steel wire. Only the pilot size varies, from 3/32" up to ¼".

http://www.spiralbrushes.com/end.html


Title: Re: Story of a Transmitter Restoration
Post by: John K5PRO on September 03, 2009, 12:31:06 AM
Is that red glyptal or just paint on the soldered connections? What is it's purpose? Have seen that in mil. equipment of that vintage. Nice work - you obviously didn't rush it.
73


Title: Re: Story of a Transmitter Restoration
Post by: W1VD on September 03, 2009, 06:09:34 AM
Quote
Pilot Bonding Brushes...

McMaster has them. Nice tool...

http://www.mcmaster.com/#power-brushes/=3gv25l (http://www.mcmaster.com/#power-brushes/=3gv25l)


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 03, 2009, 06:44:57 AM
Is that red glyptal or just paint on the soldered connections? What is it's purpose? Have seen that in mil. equipment of that vintage. Nice work - you obviously didn't rush it.
73

It's red glyptal.


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 21, 2013, 10:40:46 PM
At last !

BigRig has finally returned to the airwaves.  After a couple of false starts a few months ago, when the power supply chokes kept failing, I finally got that sorted out.

As of 3 weeks ago, I've been bothering everybody on 40 AM and I've done more hamming in the past 3 weeks than I've done in non-repeater operating in the past 3 years!

What great fun, and a lot of nostalgia.  It's hard not to get a little teary-eyed when operating the rig and remembering back to using it nearly 70 years ago as a kid, while sitting on my dad's lap.

Another thanks to everybody who contributed advice, counsel, and parts, and a special thank-you to the more-than extremely-generous local ham with the fabulous old-timer's junk box, who wishes to remain anonymous.

BigRig has been getting gratifying reports on and about 7290.  Look me up!

73.

-al hart, w8vr
al@w8vr.org


Title: Re: Story of a Transmitter Restoration
Post by: W3RSW on September 22, 2013, 07:51:22 PM
Absolutely gorgeous!

What is the smaller box between the modulator and driver and final decks?

Truly a 3705 / '33 set and forget Big Rig.  8)
Bet it has Presence


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 23, 2013, 08:22:07 AM
Tnx, OM, fer the "absolutely gorgeous" comment!!

Above the modulator is the modulation-monitor scope, and above the scope is the exciter, then the final.

And forgive me, but I don't understand your last comment.

73.

-al hart

www.w8vr.org



Title: Re: Story of a Transmitter Restoration
Post by: N2DTS on September 23, 2013, 08:42:08 AM
That came out REAL nice!

Running home brew stuff is the most fun way to operate.


Title: Re: Story of a Transmitter Restoration
Post by: W3RSW on September 23, 2013, 09:40:06 AM
Presence

http://dictionary.reference.com/browse/Presence (http://dictionary.reference.com/browse/Presence)

Particularly definitions 6 and upwards.  ;D



Title: Re: Story of a Transmitter Restoration
Post by: W3GMS on September 23, 2013, 10:16:16 AM
Wonderful job Al!  Very nice restoration which I am sure took countless hours but well worth the effort.  Whats more impressive is that your using it on the air.  Why have something if you one does not use it.  I can't wait to catch you sometime on 40 meters.
73,
Joe, GMS


Title: Re: Story of a Transmitter Restoration
Post by: John Holotko on September 24, 2013, 01:15:57 PM
Really nice work. That is class.  Looks beautiful.


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 24, 2013, 01:55:03 PM
Thanks Joe, and thanks John and thanks to all the other respondents!

The many compliments about the rig help a great deal to offset the hundreds of hours and thousands of dollars that went into the project!

Yes, for far less money and far less work, I could have bought something that might transmit better, but the goal here was not necessarily to acquire the world's best transmitter.  The goal was to re-build my father's creation.  A labor of love, so to speak.

Throughout the rebuilding, I had to re-create all the schematics, mechanical drawings, cabling drawings, do all the operating calculations, document the project photographically and textually, and so on.  When I originally inherited the rig on the OM's passing in 1957, for some inexplicable reason, he had left not a single scrap of paper about the rig.  As a kid, I used the rig with darn little knowledge of how it worked.  Now, even as a retired EE, it still took a long time reading pre-war QSTs. handbooks and other old literature about the technology of the '30s and '40s to remember all that stuff.

I was often sorely tempted to revise something or to add something, as the engineer in me tussled with the tension between what was "right," what was "state of the art," and what my dad had originally built in 1945.  The main revision I allowed myself was converting all the 120 ac wiring to 3-conductors, in the interest of future safety.  There were a couple of other minor revisions but it's largely what it was.

Regardless of all that stuff, every time I hit the transmit switch, my mind goes back over a half century to when I was using it under two calls as K8RJC and VE1VI/W9, and even further back to when it was built and used by my SK OM, VE1MZ and W9IVP.  It's hard not to get a bit of nostalgic sadness now and then.

For further info, be sure to read the text on the website.  Click on the Turner 99 mike!

Many thanks again, es 73.


-al hart

www.w8vr.org




Title: Re: Story of a Transmitter Restoration
Post by: W3GMS on September 24, 2013, 10:16:11 PM
Sticking to your original goals served you well on this project Al. 

Now, maybe you will build another rig for another reason and that will be the opportunity to include all of those improvements.

Let me know when your on 40M and we can make a sked.  I would love to hear it on the air.

73,
Joe, W3GMS 


Title: Re: Story of a Transmitter Restoration
Post by: ashart on September 25, 2013, 08:11:57 AM
Hello agn, Joe -

Nah!  No more rig building for me - that ship has sailed.  I'm 78 and my budgets of time and money have both been depleted.  I'll still play with my electronics and my photography, but no more big projects.  (That's unless of course, I run across a homeless BC-610 needing some TLC!  :)

My biggest concern now is finding a future home for the rig.  I'd sure like to find a museum to which I could donate the rig and its spare parts and documentation, and which would display and/or use the rig so that future new hams could see what the technology of the '30s and '40s looked like.  The League yawned a lot when I mentioned the project a few years back and my understanding of AWA also suggests it would not be interested.

As to a 40 meter sked, I'd be more than happy to work you, and as my time is fairly free, and because you undoubtedly know more abt 40m propagation than I, why don't you find a good time and one convenient to you and ship me an email via al@w8vr.org.  If I can possibly make it, I sure will.

73.

-al hart
www.w8vr.org
 


Title: Re: Story of a Transmitter Restoration
Post by: N2DTS on September 25, 2013, 08:38:58 AM
There are a FEW younger guys around on AM, and that is likely the only place that rig would find a safe home.
By younger, I mean in their 40's or early 50's.

Not too long from now, there is going to be a LOT of this old gear and no one wanting it at all...

I know many older guys with huge amounts of unused prime parts who have not operated for 20 years.
Vintage rigs, homebrew stuff, parts, tubes and iron.

It will sit in the basement/garage till they need to move out or keel over, then it will go in some dumpster I suppose.




Title: Re: Story of a Transmitter Restoration
Post by: KC2TAU on September 25, 2013, 10:52:57 AM

Don't worry, there are still a few young folks interested in AM. I'm 25 and use a Collins ART-13. I recently restored a Hallicrafters S-76 (I have a thing for meters). I have also have a particular enjoyment of WWII era military issue items.

I have a friend who is about my age who recently picked up a Hammarlund HQ-150. Him and I go tube hunting on the weekends.

Al, I posted a link to your photo album on my Facebook page and tagged some of my friends who are mechanically and electrically inclined and they were really, really impressed with your attention to detail. Your level of craftsmanship really is an inspiration.


Title: Re: Story of a Transmitter Restoration
Post by: W3GMS on September 25, 2013, 10:54:30 AM
Hello agn, Joe -

Nah!  No more rig building for me - that ship has sailed.  I'm 78 and my budgets of time and money have both been depleted.  I'll still play with my electronics and my photography, but no more big projects.  (That's unless of course, I run across a homeless BC-610 needing some TLC!  :)

My biggest concern now is finding a future home for the rig.  I'd sure like to find a museum to which I could donate the rig and its spare parts and documentation, and which would display and/or use the rig so that future new hams could see what the technology of the '30s and '40s looked like.  The League yawned a lot when I mentioned the project a few years back and my understanding of AWA also suggests it would not be interested.

As to a 40 meter sked, I'd be more than happy to work you, and as my time is fairly free, and because you undoubtedly know more abt 40m propagation than I, why don't you find a good time and one convenient to you and ship me an email via al@w8vr.org.  If I can possibly make it, I sure will.

73.

-al hart
www.w8vr.org
 

Hi Al,

I am sure you will find a home for that transmitter.  I am 61 and think I still have a few more years left in me so one never knows.  We can discuss that further when we chat.  

As to a time, lets try tomorrow (Friday) at 1PM on 7.285 +/- QRM.  

I will also send you an email.

73,
Joe, W3GMS  


Title: Re: Story of a Transmitter Restoration
Post by: W3GMS on September 25, 2013, 10:58:00 AM

Don't worry, there are still a few young folks interested in AM. I'm 25 and use a Collins ART-13. I recently restored a Hallicrafters S-76 (I have a thing for meters). I have also have a particular enjoyment of WWII era military issue items.

I have a friend who is about my age who recently picked up a Hammarlund HQ-150. Him and I go tube hunting on the weekends.

Al, I posted a link to your photo album on my Facebook page and tagged some of my friends who are mechanically and electrically inclined and they were really, really impressed with your attention to detail. Your level of craftsmanship really is an inspiration.


Your story is a good one and I hear similar stories from time to time.  You and other will keep the filaments lit for quite some time. 

You will always hear the doom and gloomers and everyone deserves to give "their" opinion!   

Joe, GMS


Title: Re: Story of a Transmitter Restoration
Post by: N2DTS on September 25, 2013, 11:24:24 AM
Well, I hope I am not a gloom and doom person, just realistic.
I suspect there is a LOT of good stuff out there that not many will want in the future.

When I was young, I was into the stuff that was out then, CB radios (was different back when you needed a licence), heathkit, and other radios.

I got into AM and picked up slightly vintage gear as the solid state stuff was no good for AM (and still is not).

Someone young, if interested in radio (unlikely) would be more interested in SDR and computers I would think.

I think the average age of people I work on the air is about 65...but that might low..

I wonder how many people there are in the US that run AM at the moment.


Title: Re: Story of a Transmitter Restoration
Post by: W1RKW on September 25, 2013, 05:34:11 PM
Nice work Al. Glad you took the time to do ALL the detail work. 

When I built GORT I payed attention to certain details and others I did not. Those that I didn't I figured I'd get back to and finish up. I was in a hurry to wrap up the building because it was either build it or dump it. It took 12 years with a 5 year hiatus in between.  But I wish I took the time to do the detail work that I ignored but it works. 

Hope to hear your rig and good work OM. Outstanding!
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands