Stroboconn

[Bart]

I recently acquired an old Stroboconn tuner (6T5) that I'm going to bring back to life (hopefully!). First order of business: making sure the transformer works, so it won't immediately blow its fuse with the Dutch 230V AC. It looks like it's in a good condition, so I hope I won't stumble into too many problems. I also found the schematics, so that will help as well.

Do you have any first-hand experience with this old tuner? As a musician? Or maybe as technician? I've only once seen one in Europe, but I'm sure they were more popular in the US. I'm very interested in your experiences!

[SimmonsTrombone]

With old radios, I always pull the rectifier tube to be sure any bad capicators in the power supply don’t blow it. I don’t know if the Strobocon had a rectifier tube or not.

[timothy42b]

I don't remember the circuit but anything that old probably has failed electrolytics. Check ESR before powering up.

It was a really ingenious design. And it cost as much as a car back then.

[bassbone]

No experience as a technician, but I remember one being in the band room when I started in 5th grade!

[BGuttman]

I hope it came with a microphone. I don't know if it would work with modern microphones.

Definitely open it up and verify that the electronics looks intact. Any white or black crusty stuff anywhere is a red flag. Also, pull all the tubes and see if you can find a place to test them.

I played in one band that had one and we tuned to it. Interesting wtching it "click"into tune.

[Leisesturm]

I hate being the Debbie Downer, but ... surely there are better ways to spend time? I mean ... if the thing works, yay. But if it does not. Well, I for one would practice instead. The Tonal Energy app on my Iphone has completely replaced my perfectly functional top of the line Korg OT-12 orchestral instrument tuner. I paid good money for that tuner and nothing else on the market (except maybe a Stroboconn) would be able to tune the lowest pipes of a 32' stop on a pipe organ. But ... time marches on. I used to have the curiosity necessary to want to do projects like this but I didn't have the follow through. Now I have neither the curiosity or the visual acuity. Good, because Radio Shack is defunct and that may have been the one place where someone trying to resurrect a piece of legacy electronic technology might find replacement parts. FWIW

[Bart]

Thank you all for your advice and stories!

I hope it came with a microphone. I don't know if it would work with modern microphones.

It did come with a microphone: an Astatic JT-30. That should be a microphone that works with Stroboconn, if my little research is correct!

I hate being the Debbie Downer, but ... surely there are better ways to spend time? I mean ... if the thing works, yay. But if it does not. Well, I for one would practice instead.

I agree with you, there are probably thousands of better ways to spend time. But I bought is as a hobby project and I treat is as such. I won't go to extreme lengths to repair it, but I would love to see what I can do to make it function again. Even though there are wonderful and easy alternatives these days to a Stroboconn: I would love to have it working in my practice room. And after all: there are still worse ways to spend time

[ghmerrill]

I think you should get a Jacob's ladder to go with it. What a cool combo.

[Kbiggs]

If restoring it is just for fun, then this probably won’t matter.

I remember that it took a long time for them to warm up, and that as they got warmer (say 20 or 30 minutes of use) their accuracy wavered. It’s been 35+ years since I saw one, so I don’t remember whether they went flat or sharp, or if it was a different pattern... perhaps they expanded from the middle or shrank from the middle...

Regardless, have fun with it!

[mwpfoot]

Very cool. I have some thrift store combo amps and powered mixers that need new caps etc. but I'm stuck in the "find time to clear some bench space" phase that indefinitely precedes every electrical project.

[ArtL]

If the tuner turns out to be a dud, there is some value in the mic; the JT-30 is one of the classic harmonica mics for blues. Grab the mic, a harp, and a tube amp, and go to town!

[Bart]

If restoring it is just for fun, then this probably won’t matter.

I remember that it took a long time for them to warm up, and that as they got warmer (say 20 or 30 minutes of use) their accuracy wavered. It’s been 35+ years since I saw one, so I don’t remember whether they went flat or sharp, or if it was a different pattern... perhaps they expanded from the middle or shrank from the middle...

Regardless, have fun with it!

Thanks for the feedback! The funny thing is that the manual says: "Where extreme accuracy is demanded, the Stroboconn, like other electronic measuring devices, should be allowed to run for 30 minutes before using. This permits all electrical and electronic components, as well as the fork, to reach temperature stability." But that might just be the theory

It is "just for fun", but I would love to get it to work correctly nonetheless! I have a transformer that works now, I have opened it up and I didn't see anything strange. I hope to have some time (time is always an issue indeed) soon to clean it up, because it has collected quite some dust over the years. Next I will let my father-in-law check the electronics/tubes (he knows quite a bit more than I do) and then I will plug it in

And if it doesn't work at all, I guess I'll be picking up an harmonica and go to town indeed

[timothy42b]

I lurk here:
https://groups.google.com/forum/#!forum ... ics.repair

and have learned a lot from the oldtimers talking about repair. It's one of the few usenet groups that aren't totally overrun by trolls.

They talk a lot about capacitor replacement in old equipment.

[Kbiggs]

Thanks for the feedback! The funny thing is that the manual says: "Where extreme accuracy is demanded, the Stroboconn, like other electronic measuring devices, should be allowed to run for 30 minutes before using. This permits all electrical and electronic components, as well as the fork, to reach temperature stability." But that might just be the theory

Well, I guess that would explain why it seemed like the Stroboconns had multiple choice tuning after letting them run for 30 minutes!

[Mamaposaune]

According to my 1955 Conn catalog, the Stroboconn sold for $695. that year. For comparison, an 88H listed for $384; a Connstellation 38H for $294., and a 6H went for $199.
My College professor had a Stroboconn in his studio - the first and last one that I ever saw.
I have a Strobotuner that I picked up at a flea market around somewhere; last time I checked it still worked. The vacuum tubes in back are readily visible.

[Bart]

Thanks again for your replies! When it works, I'm going to let it run for a while to see what the accuracy does. We've made some progress and everything appears to be in quite a good state. Haven't plugged it in yet, just checking and cleaning before anything goes wrong that could have been avoided.

According to my 1955 Conn catalog, the Strobotuner sold for $695. that year. For comparison, an 88H listed for $384; a Connstellation 38H for $294., and a ^H went for $199.
My College professor had a Stroboconn in his studio - the first and last one that I ever saw.
I have a Strobotuner that I picked up at a flea market around somewhere; last time I checked it still worked. The vacuum tubes in back are readily visible.

Very cool! Is the Stroboconn in the catalog as well? I still find it hard to fathom that it cost so much more then a trombone back then.

[Mamaposaune]

Ooops - meant to say STROBOCONN - sorry 'bout that! Will edit my post.

[2bobone]

I have several old Conn ST6 tuners that I've used for decades to tune my harpsichord. I'm sure they still have the original tubes in them and they're still going strong ! They do need time to warm up and to stabilize because they use vacuum tubes though there is a handy adjustment using 60 cycle current to zero things in once it does warm up.There is still a great place to find virtually any vintage electronic components you might need, like tubes and capacitors. Go to tubesandmorecom , the website for "Antique Electronics Supply". They stock stuff that you'd never expect to find again. Have fun --------- they're great units !

[timothy42b]

According to my 1955 Conn catalog, the Stroboconn sold for $695. that year. For comparison, an 88H listed for $384; a Connstellation 38H for $294., and a 6H went for $199.
My College professor had a Stroboconn in his studio - the first and last one that I ever saw.
I have a Strobotuner that I picked up at a flea market around somewhere; last time I checked it still worked. The vacuum tubes in back are readily visible.

Well, I'm wrong. A Chevy Bel-Air cost $1500 - $1800 in 1955, depending on options. Still, a Stroboconn was a fair percentage of that.