Erik Mandaville Posted June 7, 2006 Share Posted June 7, 2006 Since I received Bob's new tweeters, I've taken the time to rebuild my simple type 'A' networks. It's next to impossible for me to move the K-horns out from the wall to try different autoformer settings or make other adjustments, so I have installed a switching device that achieves the same thing as manually making and breaking different tap connections on the autoformer in order to attenuate the squawker. The same thing could be done for auditioning different capacitors, but that's not something I spend too much time thinking about. Inexpensive Solens work just fine for me. I also asked Bob to send along the Inductor, since I was so impressed with how the resulting network sounded with the new driver and horn. Also shown on the crossover boards is the kind of 'dress' or wiring that was done in the days before plastic zip-ties -- which are convenient and easy to use, but in my opinion do not possess the same sort of handbuilt visual effect or quality as lacing with waxed cord. I have some old radios that use the very same technique, as well as a much newer regenerative receiver that was recently built by someone who is the best electronics craftsman I know. I have always wanted to incorporate it into my own work, but just never slowed myself down enough to learn how to do. My outlook on things has changed a little in the past month, or so. Now is an excellent time to learn! I included a couple of pictures of the work. The switches are contained in a cheap plastic boxes from Radio Shack; nothing special needed there at all. I had to move some things around in order to install the midrange coil, but I'm happy with the overall result. The new speaker cables I made will have the same thing done to them. The waxed cord I bought is really tough stuff, and, when pulled tight, stays that way. The lacing on the crossover boards was done with the help of a heavy, curved needle normally used for sewing canvas, repairing sales on boats, and so forth. I will be doing the same kind of lead lacing with the new 300B Moondogs, as well as on the pair of push-pull 6L6 monoblocks I am about to start on. Erik Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 7, 2006 Author Share Posted June 7, 2006 Closeup shot of leads to the switch box: Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 7, 2006 Author Share Posted June 7, 2006 General closup showing lacing technique: Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 7, 2006 Author Share Posted June 7, 2006 ...and the subject of this post should say, ".....traditional lead dressing." Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 7, 2006 Share Posted June 7, 2006 Since I received Bob's new tweeters, I've taken the time to rebuild my simple type 'A' networks. It's next to impossible for me to move the K-horns out from the wall to try different autoformer settings or make other adjustments, so I have installed a switching device that achieves the same thing as manually making and breaking different tap connections on the autoformer in order to attenuate the squawker. The same thing could be done for auditioning different capacitors, but that's not something I spend too much time thinking about. Inexpensive Solens work just fine for me. I also asked Bob to send along the Inductor, since I was so impressed with how the resulting network sounded with the new driver and horn. Also shown on the crossover boards is the kind of 'dress' or wiring that was done in the days before plastic zip-ties -- which are convenient and easy to use, but in my opinion do not possess the same sort of handbuilt visual effect or quality as lacing with waxed cord. I have some old radios that use the very same technique, as well as a much newer regenerative receiver that was recently built by someone who is the best electronics craftsman I know. I have always wanted to incorporate it into my own work, but just never slowed myself down enough to learn how to do. My outlook on things has changed a little in the past month, or so. Now is an excellent time to learn! I included a couple of pictures of the work. The switches are contained in a cheap plastic boxes from Radio Shack; nothing special needed there at all. I had to move some things around in order to install the midrange coil, but I'm happy with the overall result. The new speaker cables I made will have the same thing done to them. The waxed cord I bought is really tough stuff, and, when pulled tight, stays that way. The lacing on the crossover boards was done with the help of a heavy, curved needle normally used for sewing canvas, repairing sales on boats, and so forth. I will be doing the same kind of lead lacing with the new 300B Moondogs, as well as on the pair of push-pull 6L6 monoblocks I am about to start on. Erik so the switch is rotory..all leads from the autoformer go into the switch..the dial connects one, and returns it to the circut? Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 7, 2006 Author Share Posted June 7, 2006 Yes -- for the most part. One pole on the switch is connected to the series inductor on the squawker, which is in series with the driver after the autoformer. The switching takes place ahead of the inductor. Erik Quote Link to comment Share on other sites More sharing options...
lwhaples Posted June 7, 2006 Share Posted June 7, 2006 Erik, Love the look! It's great you are moving ahead on your projects. Thanks for sharing! Larry Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 7, 2006 Author Share Posted June 7, 2006 Hi, Larry. Thanks for the encouragement. I'll see how it works tomorrow. In theory the switch is not different from manually disconnecting one tap in order to use another. If it's a miserable failure, I'll try something else![] Erik Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 7, 2006 Share Posted June 7, 2006 Erik, Nice job on the running lace job. I have't seen that done in a long time! I always cheat and do individual two turn ties in that situation. It's a lot easier to do. It looks like you even used the correct wax impregnated lacing cord. Al K Quote Link to comment Share on other sites More sharing options...
BEC Posted June 7, 2006 Share Posted June 7, 2006 I haven't thought about lacing since the 1960s. Used to be pretty good at it as I had to do that any time I did a repair on Air Force equipment. Then the tie-wrap came along..... Bob Crites Quote Link to comment Share on other sites More sharing options...
sfogg Posted June 7, 2006 Share Posted June 7, 2006 Hi Erik, Looks great, nice work! That is one trick I want to learn one of these days. Shawn Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 7, 2006 Share Posted June 7, 2006 cable ties -- nothing like sticking your arm into a rack full of cables all neatly bundled with cable ties, all the ends snipped off for neatness. Cuts your arm to shreds. Nice job on the lacing. That is how the Hallicrafters I have was done (no, I am not rebuilding it. I was toast and I amd salvaging it for parts). Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 8, 2006 Author Share Posted June 8, 2006 Thanks! I looked for the waxed cord locally, and couldn't find any nearby. Tandy Leather used to sell some artificial 'gut' waxed linen, but I got this stuff from an ebay-store source that turned out to be conveniently located here in Houston. Delivery was the following day, just when I got the wiring finished up. Marvel: Those Hallicrafters radios are pretty amazing inside. The schematics for those things are almost scary! A couple of years ago, I had asked a friend (the father of a couple of friends) if he would be willing to build me one of his very fine personally-designed-and-completely-scratch-built regenerative short-wave tube receivers. He happily agreed to do so, and worked on it as I was able to send him funds for parts. Of all the pieces of equipment I have, it's one that is the most special to me. An amazing example of functional design and construction, he hand-tied every inch of wiring on the entire open chassis in the same way I did my crossovers (only his work is much better than mine!) Anyway, I much prefer it to the obviously easier and more convenient zip-tie approach. Visually and functionally, I just wanted to go the extra effort to learn how to lace up wire. It's neat to me, too, that a couple of you clearly remember and used the technique. After how my hands feel today, I'm not exactly looking forward to doing the same thing on a 12 foot pair of 12AWG Teflon speaker cable.....but what the heck, it'll give me some more practice and look cool in the end. Erik Quote Link to comment Share on other sites More sharing options...
Deang Posted June 8, 2006 Share Posted June 8, 2006 That's nice looking work Erik. I would give it a try but I'm afraid I would probably end up with my fingers tied up in knots. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 8, 2006 Share Posted June 8, 2006 http://www.dairiki.org/hammond/cable-lacing-howto/ Erik, if anyone asks me to do this with my networks -- I'm hunting you down. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 8, 2006 Share Posted June 8, 2006 Erik, Beauty, eh! The networks look fabulous. Very cool. Quote Link to comment Share on other sites More sharing options...
TubeGuy Posted June 8, 2006 Share Posted June 8, 2006 Sweet work! I've laced many miles of cable in recording studios. There is nothing that compares to that look. Looks like you have mastered the technique very well. Ya gotta love true craftsmanship! Quote Link to comment Share on other sites More sharing options...
sfogg Posted June 8, 2006 Share Posted June 8, 2006 Just found this link for anyone that is curious... http://www.dairiki.org/hammond/cable-lacing-howto/ Just gotta find a source for the lace. Shawn Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 8, 2006 Author Share Posted June 8, 2006 I appreciate the feedback and compliments on this! Shawn: I think that is the same link Dean provided -- a very good one, and much more comprehensive than what I was working from. Thanks for posting that, Dean. I know you were just jokin' around, but I actually wouldn't mind doing this for anyone who wanted the same thing done on theirs. I suspect some might think it's going to an extreme, but I sort of think what seems 'extreme' in this day in age was probably thought of as pretty light labor in the past. In any event, no more zip ties for me for anything. All the components I have on hand now that I've made are going through complete zip-tie removal in order to be replaced with this approach. Shawn: I have some of what I used for this that you can have. I bought three spools of 25 yards each. I'll send you one of those if you want to give it a try. As both your and Dean's post show, there's a right way and a wrong way of doing this, and the right way sure works better! The cord I found is actually a Martha Stewart craft product I found on ebay -- sold by a seller here in Houston. I'm going to order order some more to keep on hand, and might need some more for this new pair of PP monoblocks I'm going to start as soon as I can. It sounds kind of crazy, but even lifting my drill to put the holes in those plastic boxes from Radio Shack for the autoformer switches was very difficult. Punching holes in heavy metal chassis is going to have to wait for probably two weeks or so, unfortunately. Erik Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 8, 2006 Author Share Posted June 8, 2006 Tube Guy: It sounds like you have done some very interesting work! Very neat! BTW: Is that a meshplate triode I see in your avatar? Erik Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.