If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You must be an NCRS member
before you can post: click the Join NCRS link above to join. To start viewing messages,
select the forum that you want to visit from the selection below.
My Radio was functioning fine (after 28 years of rest) but now I can't tune it past the middle of the dial. I'm a "do-it-yourselfer" and am willing to tackel anything, as long as the risk factor of me messing it up is low. So, any thoughts before I perform some exploratory surgury. Secondly, while I have it appart, should I give it a "tune" up (Yes pun intended), are there tube kits available???
As usual, thanks for the help!!
Jim
Jim, It sounds like your treadle clutch is in need of adjustment. As long as you have it apart you might as well clean the entire mechanical portion of the tunner and lubricate it. If you need it I will send you a copy of the section from the radio service manual for corvette wonderbar radios that give all adjustment procedures. I am still in awe of the design of the wonderbar section of the radio. It is a marvel of complex (for it's day), electro-mechanical engineering. Email me your address and I will send it to you. John
Jim, It sounds like your treadle clutch is in need of adjustment. As long as you have it apart you might as well clean the entire mechanical portion of the tunner and lubricate it. If you need it I will send you a copy of the section from the radio service manual for corvette wonderbar radios that give all adjustment procedures. I am still in awe of the design of the wonderbar section of the radio. It is a marvel of complex (for it's day), electro-mechanical engineering. Email me your address and I will send it to you. John
I remember seeing a tube "kit" for a wonderbar on eBay in the last few days. Don't know if it is still on or if it sold. You can look it up in completed auctions if it's alraedy off. There may be some source for these tubes, but I haven't seen it advertised.
I remember seeing a tube "kit" for a wonderbar on eBay in the last few days. Don't know if it is still on or if it sold. You can look it up in completed auctions if it's alraedy off. There may be some source for these tubes, but I haven't seen it advertised.
Jim, i forgot to address the tube issue in my earlier post. There are tubes available, but the tubes are not the weak point of old radios, the capacitors are. If you replace all the caps, then you might as well realign the radio, so to do that you would need a signal generator, then.... I would reccomend that you clean the drive train of the tuner and readjust the clutch and put the unit back together. It sounds like the radio was working fine except for the tuning problem, and once you resolve that the radio may work well for years. Cleaning and adjusting the drive train is a couple of hour job, while rebuilding the radio is a couple of day job for your first unit assuming you don't get frustrated and send it out. If you have a background in electronics and the manual you can rebuild the radio, but the learning curve is pretty steep. John
Jim, i forgot to address the tube issue in my earlier post. There are tubes available, but the tubes are not the weak point of old radios, the capacitors are. If you replace all the caps, then you might as well realign the radio, so to do that you would need a signal generator, then.... I would reccomend that you clean the drive train of the tuner and readjust the clutch and put the unit back together. It sounds like the radio was working fine except for the tuning problem, and once you resolve that the radio may work well for years. Cleaning and adjusting the drive train is a couple of hour job, while rebuilding the radio is a couple of day job for your first unit assuming you don't get frustrated and send it out. If you have a background in electronics and the manual you can rebuild the radio, but the learning curve is pretty steep. John
Thanks John & Ed, I did see that tube sed on E-bay just after I posted my request. I'll be sending John an e-mail shortly. I can't believe how much fun it is owning this car, it's been a year and a half since I got it, and I still grin everytime I walk by it in the garage (nevermind when I drive it!)! Thanks again!!!
Thanks John & Ed, I did see that tube sed on E-bay just after I posted my request. I'll be sending John an e-mail shortly. I can't believe how much fun it is owning this car, it's been a year and a half since I got it, and I still grin everytime I walk by it in the garage (nevermind when I drive it!)! Thanks again!!!
Most Wonderbar mechanisms work alike however there was a steady progression of improvement(s) over the years and when Corvette abandoned the unit in early '63 it continued to be used and refined in other cars through '65 and maybe beyond...
Ever seen a fully solid state Wonderbar? Saw one in a '65 Cadillac Hearse once--amazing, no Vac tubes and instant on response repleat with auxilary foot-switch seek actuator!
Contrary to popular impression, the seek mechanism is almost ENTIRELY mechanical. You press the seek button and a solenoid releases the spring driven tuning slider. Seek function stops on station by an in-band window comparator tripping the solenoid to disengage and stop on-station.
Interestingly enough its the sliding friction characteristics of the mechanical tuner that are required to be accurate for on-station stopping. Also, the seek mechanism as NEGATIVE design safety margin! If the radio should go into 'infinite' seek mode for whatever reason, you risk burning up the clutch solenoid. The set RELIES on the in-panel 7.5 amp external fuse to prevent damage.
The typical 'Wonderbar' syndrome is radio worked A-OK, then would occassionally blow a fuse. After replacing the fuse a few times, the prior owner got frustrated and jumped to a larger capacity fuse (say 10 amps or so). Then, something 'funny' happened. Maybe he caught the puff of smoke or it's odor (not likely in a top down situation), but the darn thing just stopped working in seek mode....
What's missing here is the prior owner 'missed' the telltale (fuse blowing) symptom telling him it was time for mechanical clean-up/tune-up and pushed the little devil over the 'cliff'..... Most of the internal parts are LONG ago GM discontinued, but those who specialize in repair get their 'stores' from gutting similar Wonderbar chassis taken from Buick, Cadillac, Etc. cars of the same period. While the packaging of the radio is different (dash layout, face plate, Etc.), many of the internal components are common to Corvette....
Sooooo, if your Wonderbar should go into 'infinite' seek mode SHUT IT DOWN you're tempting fate! If it blows fuses, it's time to pull the chassis and have it worked on. Do NOT cram a bigger fuse into the junction block!!!!!
Most Wonderbar mechanisms work alike however there was a steady progression of improvement(s) over the years and when Corvette abandoned the unit in early '63 it continued to be used and refined in other cars through '65 and maybe beyond...
Ever seen a fully solid state Wonderbar? Saw one in a '65 Cadillac Hearse once--amazing, no Vac tubes and instant on response repleat with auxilary foot-switch seek actuator!
Contrary to popular impression, the seek mechanism is almost ENTIRELY mechanical. You press the seek button and a solenoid releases the spring driven tuning slider. Seek function stops on station by an in-band window comparator tripping the solenoid to disengage and stop on-station.
Interestingly enough its the sliding friction characteristics of the mechanical tuner that are required to be accurate for on-station stopping. Also, the seek mechanism as NEGATIVE design safety margin! If the radio should go into 'infinite' seek mode for whatever reason, you risk burning up the clutch solenoid. The set RELIES on the in-panel 7.5 amp external fuse to prevent damage.
The typical 'Wonderbar' syndrome is radio worked A-OK, then would occassionally blow a fuse. After replacing the fuse a few times, the prior owner got frustrated and jumped to a larger capacity fuse (say 10 amps or so). Then, something 'funny' happened. Maybe he caught the puff of smoke or it's odor (not likely in a top down situation), but the darn thing just stopped working in seek mode....
What's missing here is the prior owner 'missed' the telltale (fuse blowing) symptom telling him it was time for mechanical clean-up/tune-up and pushed the little devil over the 'cliff'..... Most of the internal parts are LONG ago GM discontinued, but those who specialize in repair get their 'stores' from gutting similar Wonderbar chassis taken from Buick, Cadillac, Etc. cars of the same period. While the packaging of the radio is different (dash layout, face plate, Etc.), many of the internal components are common to Corvette....
Sooooo, if your Wonderbar should go into 'infinite' seek mode SHUT IT DOWN you're tempting fate! If it blows fuses, it's time to pull the chassis and have it worked on. Do NOT cram a bigger fuse into the junction block!!!!!
Jack is exactly right. The prices that people get for the solenoids is amazing.
I needed one for a radio about a year ago and the only one I could find was a salvage caddy soienoid and the guy wanter $100 for it! John
Jack is exactly right. The prices that people get for the solenoids is amazing.
I needed one for a radio about a year ago and the only one I could find was a salvage caddy soienoid and the guy wanter $100 for it! John
We use cookies to deliver our services, and to analyze site activity. We do not share or sell any personal information about our users. For additional details, refer to our Privacy Policy.
By clicking "I AGREE" below, you agree to our Privacy Policy and our personal data processing and cookie practices as described therein. You also acknowledge that this forum may be hosted outside your country and you consent to the collection, storage, and processing of your data in the country where this forum is hosted.
Tweet
Comment