1959 Wonder Bar Adjustment

[Richard J.]

Hello All... I am looking for a little guidance in how to adjust the radio in a 1959 Corvette so the wonder bar works properly. Is this the same adjustment that is on the right underside of the radio for volume/signal strength? I am trying to get the car ready for PV and I have a radio that works pretty well but the wonder bar does not work well. Is this also affected if the car is in a metal building? Thanks, Rick

[Terry R.]

Re: 1959 Wonder Bar Adjustment

Hi Rick I just had Charles Siegfried ( advertises in the Driveline) repair my '62 Wonderbar, Excellent job. Might call him for some pointers he's a great guy. And yes mine works properly in a metal building but it will depend on the strength of your stations. Good Luck

[Dennis C.]

1959 Wonder Bar Adjustment

Agree w/Terry's advice. Good luck on the PV. The test is a crap shoot on a good day. Do your homework over and over. Drive it every day while you keep going through the test. All of it, not just the stuff you like or are sure you can pass. Have your mother in law ride with you toward the end. They have judging skills beyond our comprehension. DC

[Arland D.]

Re: 1959 Wonder Bar Adjustment

Rick,

As a former local customer, I would echo Terry's suggestion to contact Charles Siegfried for any radio repairs/adjustments - he does excellent work. Regards,

Arland

[Richard J.]

Re: 1959 Wonder Bar Adjustment

Thanks for all the advise... And thank you Dennis for the Mother-in-Law idea, that may be better than any of the toughest NCRS Judges!

[Jack H.]

Re: 1959 Wonder Bar Adjustment

The seek function of the Wonderbar radio is primarily a mechanical system. You have a selection of three different signal strength levels for stopping on station (small red slide switch below the seek bar) and you may not be set correctly for your signal strength conditions OR it's quite possible to have aged/damaged radio chassis internal components here.

Bascially, when you hit the seek button, a solenoid engages allowing the mechanical tuner to 'free wheel' and a spring drives the tuner shuttle up-scale. As the tuner passes various broadcast stations, their signal strength is viewed through a vac tube constructed window comparator and the seek solenoid is de-energized on stations that are 'in window'.

The rate of tuner drift is all pre-set by the strength of the spring & the tuner's sliding friction characteristics. When radios stop but 'miss' being on-center for the station, that's a chassis internal lube/cleanliness issue. One that's very common considering the radio is vac tube based, the chassis HAS to have cooling vents to foster convection cooling and the radio sits in a 'hostile' environment (mounted in-dash in the slip stream of the cowl vent...).

The radio was never designed for 100% duty cycle seek operation. If no stations are found and the tuner hits the limit switch at the high end of the dial, that triggers a reset operation returning the tuner shuttle to the low end of the dial + re-cocking the drive spring.

The radio can withstand a few scan cycles, but continued seek + fail to capture/stop operation will overheat the control solenoid(s) and burn them out! The safeguard is the 7.5A fuse in the car's fuse panel on the radio's power line.

I've seen the 'Wonderbar syndrome' many times... Radio ages, isn't pulled for routine maintenance, gets dirty and begins to do its seek function erratically. Owners who don't understand, continue to operate the radio and notice the primary power fuse is blowing.

They get frustrated replacing fuses, so they 'bump' the replacement fuse to a higher value (10A, 15A, Etc.) and eventually there's a puff of smoke and gee the seek function doesn't work anymore... Then, the radio is pulled and discarded because a modern transistorized replacement is cheaper than finding anyone who still has the vac tube knowledge to work on their original radio!

In addition to doing basic repair, the fellow who was recommended by others (Charles) 'guts' these radios, replaces all of the discrete components known to age (like mica, and wax foil capacitors) AND incorporates ALL of the various Delco Radio published circuit updates that were recommended over the years.

So, you're getting a LOT more for you money than a simple radio repair job! There are other classic radio repair shop out there who will make the radio portion of a Wonderbar work again, but simply REFUSE to work on or guarantee the seek function of the radio because they don't understand it, don't have parts, Etc....

[Richard J.]

Re: 1959 Wonder Bar Adjustment

Thank you... All is VERY good information and it will be a big help. I will be doing more checks today. I do think I have the radio functioning well, but today will be the final test to see for sure. Thanks for you kind and very complete response! Rick

[Dave S.]

Re: 1959 Wonder Bar Adjustment

Richard,
I like the others have used Charles Siegfied numerous times and his work is nothing short of perfection and he stands behind it for 3 years. That said, if you are like me you just don't want to send everything to an expert when something small is possibly wrong.
I recieved these instructions from Charles and will pass them along in the hopes that this adjustment will solve your problem.
"Extend the antenna fully. Tune to static or a very weak station around 6 to 8 on the dial. Locate the access hole on the bottom of the set toward the back for the ANTENNA TRIM SCREW ADJUSTMENT - see tag. Turn screw for maximum volume. You should find a definate peak within a turn or two either direction."
Best of luck with your PV.

[Richard J.]

Re: 1959 Wonder Bar Adjustment

This is the adjustment I found yesterday and I am sure glad I got a reaffirming answer on what could be done. I did my testing around 10 on the dial and yes, you can definitely hear a "sweet" spot. Thanks for your kind reply and wishs on the PV in Seven Spring! Best regards, Rick

[Dennis C.]

Wonder Bar Adjustment

May I add... Regarding Charles S., Years ago when I called him early on in my hobby involvement, he seemed very willing to help solve a problem on the phone without requiring any charge or a "just send me your radio" - instead great free advice. There are other vendors out there that will do this, (JDG for example), but not many. Best, Dennis