About
Hi, and thanks for reading! I’m J.W. Koebel and I’m a technologist based out of Seattle. On weekdays during business hours, I’m a project manager helping clients adopt enterprise human resources automation software. It’s a great product. The rest of the time you’ll find me working on technology projects of all kinds and writing about the results here on my blog. If you’re looking for more info on my career, there’s a LinkedIn button on the right – this blog is dedicated to everything else that’s going on in my life. Feel free to send me questions and comments to “jkoebel (@) gmail (.) com” and if you use GPG/PGP, I have a Public Key linked and attached to the About Me text at the top of this page if you’d like to send me a secure message.
I stay active juggling a bunch of projects that probably involve electricity in some way with enjoying all the natural beauty the Pacific Northwest has to offer. I fix up antique tube radios for my private collection and for clients, salvage/repair/recycle more modern electronics, create interesting IT projects on my own, build things, make things, and document it all. There’s also biking, hiking, scuba diving and skiing. If I find a way to combine the two different sets of hobbies, it will definitely be featured in an article.
Feel free to leave a comment on any page, and to visit any of the profiles in my sidebar.
Hey! I have a question about the Edcor power transformer you used in the Zenith 7s363. Please get back to me
Hi there…wpould you be interested in buying a philco radiobar (working) with a a full set of the originla glassware??. respond to Grantmoore@verizon.net
I have the exact SAME radio as you have posted on your site… how much is it worth.?
I have quite a few posted here – which one specifically?
I am searching for a chassis and speaker for a Stromberg 520 table model. Any help, leads,etc. would be greatly appreciated.
Jim
Hi, I have a Philco 44 console (do not know which model) has been in the family since new. would like to have the radio either replaced or restored. I would like a bid from you. Thanks.
Dear Mr. Koebel,
My name is Mark Van Sickle and I own a pair of Bose 901 series speakers. I’m looking for someone to refurbish my “Active Equalizer”. It works, but the mode switch is old and oxidized and the left channel cuts-out if you change the switch setting. Please email me with contact/shipping information as soon as you can.
Sincerely,
Mark
Thanks for your interest, Mark. I’ve followed up with you via e-mail.
Hi again,
I received your reply on the 589 grunow restore you did.
I wonder if you can anser a question for me.
IMy grunow 589 has the shielded wire broken off on the volume seitch and the tone control switch.
I am having trouble with the schematics, and wonder if you could tell me which of the 3 terminals on each switch the shielded wire goes to?
Hard to make out in the pics, and I want to get it right.
WHat is the purpose of the sheild?
Is it necessary to ground these wires individually with the metal shield?
Thanks for your help, I hope.
THis thing of mine has been butchered and it makes it hard to re-build when someone else has done a sloppy job at what they did.
Have a nice day,
Kevin
On the volume control, it should go to the wiper (center of the 3 adjacent tabs). As far as the tone control, maybe some of these saved photos that weren’t in the article can help. I don’t have a 589 in front of me to give any more detail.
https://lh4.googleusercontent.com/-JfZgsXjQAuo/TbeYQBLAGFI/AAAAAAAAFN4/bc1qy-TUXqw/s800/IMG_20110424_171955.jpg
https://lh6.googleusercontent.com/-4Gm5z62SKxA/TcDNDPnhndI/AAAAAAAAFSE/9UmZayeF8e8/s640/IMG_20110503_204527.jpg
https://lh3.googleusercontent.com/-fQNQJmE-JUg/TgfAVYdCIsI/AAAAAAAAFzE/bTMXn_vw5VI/s800/IMG_20110626_160120.jpg
https://lh3.googleusercontent.com/-H2mJxF62LOA/TsrBBKMA-9I/AAAAAAAAG4o/TsC75rA5H1k/s800/IMG_20111120_150738.jpg
Hello again fellow radio junkie,
Have a simple question for someone with your backround.
Putting electrolitics in the 589 chassis.
Noticed one of the cans has a single lead, and the other has a center lead and another coming off of the same can. It goes to a terminal board on the other side of the chassi .
Does not appear to be a ground wire.
Could you tell me where this second lead is wire to on the new electrolitic?”
I could send a pic if I had your direct email?
Sorry to bug you again.
Kevin
Kevin, this radio has a negative filtered power supply. The + of both capacitors can tie together on the rectifier filament; one – will go to chassis (the can with only lead going to it), and the other – will go to the center tap of the HV secondary (the one where the lead goes to a terminal strip). For the electrolytic being replaced which grounds through the can to chassis, just pick your favorite chassis tie point and solder the – lead to that.
In many radios, chassis and the B- center tap are at the same potential, but in this case they’re separated by the field coil’s voltage drop. It’s a cheap way to establish bias voltage.
Thanks pal, That 2nd wire kind of threw me on that other can. I checked it for continuity to ground and found it was not a ground wire. Will tie the negative on that electrolitic to that brown wire which goes to the terminal strip on the other side of the chassis? Thanks for your help. Kevin
That sounds right to me, but you can double-check. Measure continuity to either pin 2 or 3 (plates) of the rectifier from the tie point you’d like to attach to. That wire should trace from the terminal strip back to the transformer and disappear inside the bell. This might have up to 500 Ohms of resistance, as there’s a lot of very small wire in there.
Please send me any photos you’ve taken along the way to jkoebel [at] gmail (dot) com, I’d love to write up a short article with a kind of Grunow 589 FAQ drawing on the 3 sets worth.
Hey there,
Thanks for your help.
Have the electrolitics in now.
Have to replace the tone control switch, which I thin is only half wired.
Seems the previous owner thought that if anything went haywire, you just cut the wires and remove them from the chassis.
THe band switch has all wires removed from chassis as well.
THink I will just get the tone control switch hooked up, and forget about the SW band.
HAve an easy to read wiring diagram for the tone control switch?
I think after I install the new switch and finish re-capping, I will be done with the chassis.
I have it playing on the AM band now.
Volume could be louder, but I am thinking the re-cap will help that.What do you think?
Have a great weekend.
Kevin
Here is a question?
I have heardf from someone that back in the 30,s, the government banned shortwave on certain models of radio’s.
That would explain why my 589 has a band selector switch, but it is not wired.
Ever heard of this?
Have a great weekend and I will send you a pic of the completed radio once I figure out how to wire in the new tone control switch.
Kevin