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egg
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Wed 05, 2019 9:44 pm |
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Joined: Jan Tue 31, 2012 1:55 am Posts: 10367 Location: Mountains of Mourne. Ireland.
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Very good John. I'm with you, no shelf Queens here either.  Greg. oh... is there a serial number present ?
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Sat 08, 2019 11:50 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Tue 18, 2019 4:03 am |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Wed 19, 2019 6:06 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Progress !!!
Shaun kindly sent me a couple of Nu-Gold alloy discs which he uses for Sony TR-6 brights to replace the one which was missing from this set's volume knob. They look very much like originals seen in pictures, but have to be reduced in diameter and thickness to fit knob cavity. He also told me how he reduced the diameter, but I wanted to come up with an easier method using items at hand. First thought was to center and glue a large bolt to bottom of disc so that it could be chucked into drill, but was concerned about removal when complete. Remembered having a few scrap pieces of thin but good quality self-adhesive Velcro and decided to give it a try. Cut a section just large enough to fit within "finished" diameter and attached to disc and head of bolt after cleaning both with Q-tip and Isopropyl alcohol. Separated the Velcro elements and carefully centered the bolt head, then inserted into electric drill. It worked fine with just a bit of "wobble" while sanding edge with 180-grit sandpaper. Gently "swept" the sandpaper back & forth during process changing areas on surface while maintaining firm but gentle, perpendicular contact. Still took a long while to remove around 1/16" of material, but much less difficult than using a file or sandpaper by hand... Used inside calipers to determine needed O.D. and also checked fit periodically as it became closer to required size. It was clear by the depth of knob cavity that the new disk was also much thicker than original (as Shaun had mentioned in e-mail) and needed to be sanded thinner by simply rubbing across sandpaper on flat surface until fit looked right. Looking at pics of other sets, didn't get it quite thin enough, but very close... Went over outside surface of new bright several times with Novus-2 and cleaned back with alcohol. Very carefully scraped old glue from inside of knob cavity and also cleaned it with 91 % Isopropyl alcohol. Applied a small drop (so it wouldn't "ooze" out edge) of Loctite Go-2 glue in center of knob cavity and pressed in new bright---looks great and very much like original ! Thanks again Shaun !
After gluing loose right-side ferrite-rod antenna mounting pad back onto PCB and then gluing rod to both pads, was able to wrap and attach ends of remaining black factory support tape on to bottom of PCB with tiny amounts of Superglue gel to retain original top-side appearance. Also "re-flowed" wax on windings where they had been chafed during movement when rod was loose inside cabinet during shipment.
Had earlier thought since it was rubbing cabinet top, that the volume knob had been "jammed" down on control shaft and had loosened setscrew and pried up carefully with screwdriver tip on inside. Then discovered after removing the earphone storage compartment that the entire control mount bracket was adjustable ! So restored knob to original & correct position on shaft and adjusted bracket for proper height (which also centers the "graphics" within front panel window).
Since I couldn't loosen the earphone jack nuts and didn't want to risk damage, decided to leave 'em along with speaker and volume control attached to cabinet. Because of this, cleaning cabinet was a bit tedious. Not very dirty, but a lot of residue in grooves which I was able to clean with just a water-dampened toothbrush using Windex or Isopropyl alcohol on stubborn spots on plastic. Carefully cleaned speaker grille using water-dampened, then dry inside-out white cotton sock pieces---the "nubs" help with the holes... Water-dampened, then dry Q-tips and small pieces of cotton cloth for most the rest in & out... Was very careful cleaning around the original foam rubber pads inside back cover since they were still intact...
Reinstalled PCB and reconnected battery contacts and solar-handle mounting blocks wiring. Had to remove volume control mounting bracket screw to install earphone storage compartment and then needed to realign control position. Temporarily attached handle mount blocks to cabinet with short, slotted 8-32 screws until proper hardware found.
Was very nervous about cleaning dial window because of reverse painting---but thankfully had no problems... First rinsed thoroughly with cold water, then wiped inside VERY gently with water-only saturated piece of soft cotton cloth, rinsed again and then wiped VERY gently again with dry soft piece of cotton cloth and blew off thoroughly with low pressure compressed air. Went over outside surface several times with Novus-2 to remove light scuffs/scratches. Also polished both sided of clear tuning knob to remove some light scuffing which appeared to be from manufacturing process.
PCB had to be removed to install tuning knob, then mechanically aligned to center shaft in cabinet hole so that knob wouldn't rub or bind.
Radio itself is now complete ! Installed batteries and it's an excellent performer at upper-end of dial with lower side being somewhat deaf as several others in collection... Sound very good for such a small speaker---very neat to listen to oldies and look at this imperfect but beautiful radio !
Now on to the handle and solar pack surgery ! And to find the proper brass thumbscrews for mounting...
Pics in two groups below...
John
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ARF HOF BOLT VELCRO BRIGHT1.jpg [ 297.22 KiB | Viewed 1115 times ]
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ARF HOF BOLT VELCRO BRIGHT2.jpg [ 290.3 KiB | Viewed 1115 times ]
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ARF HOF NEW BRIGHT IN.jpg [ 125.53 KiB | Viewed 1115 times ]
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Wed 19, 2019 6:13 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Colin Ames
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Wed 19, 2019 8:46 pm |
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Joined: Aug Wed 26, 2009 1:50 am Posts: 1559 Location: Mesquite NV 89027 (from Coventry, UK)
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Looks great! I like the method you used for modifying the knob brights.
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Sat 22, 2019 3:13 am |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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50sTransistorRadios
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jun Sat 22, 2019 4:36 pm |
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Joined: Sep Sat 29, 2012 6:32 pm Posts: 921 Location: 13760
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That "nu-gold" bright turned out great, I'll have to look into that material! I hope you can get that solar handle repaired to your satisfaction as well.
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Thu 04, 2019 4:09 am |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Thanks Matt---appears to be several selling them on-line. They're also available in different thicknesses...
Thought I'd devote an entire post to a great, helpful, and much-needed home-made gift from Shaun (after receiving his permission).
The two polished brass thumbscrews were missing from this radio and had been replaced with two double-slotted brass truss-heads. Had asked about a source for possible replacements and Shaun made this remark in a subsequent e-mail along with a link to 1" brass rod stock on Ebay: "Hi John, If you have a mini-lathe and a knurling tool and a tap and die set there's this (smiley face & link). I can give you precise dimensions if you need it." ...
10 days later he asked the length of screws used on mine since my handle was different...
Then, almost two weeks after his remark about a mini-lathe, received this e-mail along with some pics: " Hi John, Lets face it, I think your never going to find thumbscrews from a unloved junked Hoffman.
Lucky for you I got a piece of 1inch brass rod and thought I would have a go making some. I do have a mini lathe, knurling tool and tap and die set. I didn't want to say anything until I tried.
I am not attempting to do the cut in the middle as on the original, and the two ends are kind of different. Note once you get that much cut into for the screw you really don't want to mess around with the end or cutting grooves in the middle.
Also the original is just under one inch. Apart from that they should be pretty good copy. I even got the dip in the middle.
I'll pop them in the post if you want them on Monday. Hopefully they will help you finish. You may need to put some brass offsets to get the length correct.
Good luck Shaun"
Received the two home-machined and well-polished thumbscrews a couple days later and they are just beautiful ! What a thoughtful, generous, and helpful gift that required a lot of tedious effort ! Thanks again Shaun, VERY much---Sure appreciate your help with this project !
Few pics below from Shaun---the last one was taken here after they arrived...
John
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ARF SHAUN LATHE.jpg [ 375.19 KiB | Viewed 974 times ]
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ARF SHAUN HOF T-SCRWS IN PROCESS.jpg [ 246.29 KiB | Viewed 974 times ]
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ARF SHAUN HOF 1ST T-SCRW I-P THREADED.jpg [ 328.66 KiB | Viewed 974 times ]
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ARF SHAUN HOF T-SCRW IN WRK COLLAR.jpg [ 255.82 KiB | Viewed 974 times ]
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ARF HOF THUMBSCREWS FROM SHAUN.jpg [ 152.21 KiB | Viewed 974 times ]
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fifties
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Thu 04, 2019 5:46 am |
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Joined: Jan Thu 01, 1970 1:00 am Posts: 33314 Location: SoCal, 91387
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Incredible workmanship! You owe this guy (you know that though).
_________________ \\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins//////////////////
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livewire54
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Thu 04, 2019 5:47 am |
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Joined: Mar Tue 12, 2019 6:09 am Posts: 142
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Can't wait to see the finished "objet d' arte" with the new hardware in place! Those thumbscrews are drool worthy.
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mrx
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Thu 04, 2019 6:50 pm |
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Joined: Jan Thu 01, 1970 1:00 am Posts: 3480 Location: Massachusetts
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My favorite Hoffman, or Sony TR-6
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Sun 07, 2019 2:24 am |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Note the quality of machining & polishing in the "face" of the thumb-screws---The uniform reflections sure resemble Yin Yang symbol !
John
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Colin Ames
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Sun 07, 2019 3:32 am |
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Joined: Aug Wed 26, 2009 1:50 am Posts: 1559 Location: Mesquite NV 89027 (from Coventry, UK)
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That was incredibly decent of Shaun to make those screws. What a fine fellow!
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Jul Sun 07, 2019 4:52 am |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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You're absolutely right Colin---was so surprised and amazed when I received e-mail (with pics) stating that he had, that I had a hard time finding words to respond with in gratitude ! Sure looking forward to getting handle together so they can be installed !
Haven't mentioned the mishap with a couple solar cells awhile back where the solder strip at edge of silicon came off when trying to reattach to array. Found on-line that conductive silver epoxy may work, so am researching a bit... Anyone else use it for that application ???
John
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Sep Sat 21, 2019 10:32 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Hello All,
Haven't forgotten this old "treasure" !
Finally got up the nerve today to glue the brass handle-mount blocks to insides of repaired cabinet. Very carefully used Loctite Go-2 glue which has proven itself very good on several projects. Inserted 2.5 mm screws of needed length through short pieces of Teflon tubing with O.D. just under that of 8-32 screw to prevent glue from entering threaded holes. Once glue applied and block placed into proper position, put small flat-washer and nut on end of screw and tightened to hold part securely against plastic until cured.
Then revisited article found awhile back on Indium-alloy soldering for silicon solar cells and posted in Clubhouse to see if anyone here had used it---need as much help as I can get to reconnect those elements !
Still haven't found drill-press to borrow for handle cover holes, but continuing to look...
Hopefully one day it will be complete and can show off Shaun's beautiful thumb-screws !
John
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Ed Morris
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Sep Wed 25, 2019 1:20 am |
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Joined: Jan Sun 06, 2008 3:28 am Posts: 4416 Location: Richmond, VA
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Looking forward to it!
_________________ Ed
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Oct Thu 03, 2019 4:56 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Hello All,
Radiohenry responded to my Clubhouse post on indium soldering and very kindly sent me some samples to experiment with along with suggestions on how to use it. Unfortunately, it didn't bond well to the silicon as hoped, even after proper preparation---may need a special flux. But the really bad news is that I physically broke one of the cells during process effectively killing this portion of project---arghhhh ! So may try to find newer solar elements which will fit inside handle and function and keep the original cells with ALL the other factory parts that were replaced. Am trying to keep anything I do to this rare, historic radio easily reversible so that it could be returned to original state (other than the glued plastic)...
Still searching for a drill press to borrow to complete new handle cover...
John
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3Transistors
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Oct Wed 09, 2019 8:07 pm |
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Joined: Aug Sat 16, 2014 2:19 am Posts: 1388 Location: Palos Verdes, CA
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xrhonda91
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Post subject: Re: UNBELIEVABLE Ebay find---'57 Hoffman Solaradio BP-411 !! Posted: Oct Wed 09, 2019 10:46 pm |
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Joined: Oct Mon 26, 2009 10:02 pm Posts: 6198 Location: Indianapolis, IN
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Thanks Mark !
Am thinking that some of the rechargeable lawn lights have panels that may fit handle openings and am keeping eyes open for junked units... Of course, will install them so that they can be easily removed and radio returned to originality for next owner one day...
John
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