Circuits & Concepts

Yep.  When the trim capacitor oxidizes, it can go open.  That makes the PLL IC lose its mind.  Time for a fresh trim cap! 

Les

Welcome, Matt!

I suggest you get the power supply sorted out before doing anything else.  I typically probe the rectifier diodes to do this.  Red meter lead on the diode of interest and the black lead on the chassis.  Measure and log both the DC and AC voltages. 

The AC voltage (on the rectified side of the diode) should be lower than 0.1 VAC.  Something higher indicates a bad power supply capacitor, which will mess up the regulation.

The kit you ordered from C & C includes the resistor R635, new speaker relays and a trim cap for the tuner.

The high efficiency regulator I make replaces the 4 hot resistors on the main/amp board, and includes replacements for the 4 hot resistors on the noise reduction board.  You shouldn't do that upgrade until the rest of the receiver is fully functional.

 Hope it goes well!

Les

Welcome to the site, Brian!

Hearing from Tooele takes me way back... years ago I worked at the Hercules rocket plant in WVC. 

Cheers!

Les

Grandpa The Gambler

The IRS decides to audit Grandpa, and summons him to the IRS office. The auditor was not surprised when Grandpa showed up with his attorney....

The auditor said, "Well, sir, you have an extravagant lifestyle and no full-time employment, which you explain by saying that you win money gambling. I'm not sure the IRS finds that believable."

"I'm a great gambler, and I can prove it," says Grandpa. "How about a demonstration?"

The auditor thinks for a moment and said, "Okay. Go ahead."

Grandpa says, "I'll bet you a thousand dollars that I can bite my own eye."

The auditor thinks a moment and says, "It's a bet."

Grandpa removes his glass eye and bites it. The auditor's jaw drops.

Grandpa says, "Now, I'll bet you two thousand dollars that I can bite my other eye."

Now the auditor can tell Grandpa isn't blind, so he takes the bet. Grandpa removes his dentures and bites his good eye.

The stunned auditor now realizes he has wagered and lost three grand, with Grandpa's attorney as a witness. He starts to get nervous.

"Want to go double or nothing?" Grandpa asks. "I'll bet you six thousand dollars that I can stand on one side of your desk, and pee into that wastebasket on the other side, and never get a drop anywhere in between."

The auditor, twice burned, is cautious now, but he looks carefully and decides there's no way this old guy could possibly manage that stunt, so he agrees again.

Grandpa stands beside the desk and unzips his pants, but although he strains mightily, he can't make the stream reach the wastebasket on the other side, so he ends up urinating all over the auditor's desk.

The auditor leaps with joy, realizing that he has just turned a major loss into a huge win. But Grandpa's own attorney moans and puts his head in his hands.

"Are you okay?" the auditor asks.

"Not really," says the attorney. "This morning, when Grandpa told me he'd been summoned for an audit, he bet me twenty-five thousand dollars that he could come in here and pee all over your desk and that you'd be happy about it!"

Has anyone measured the frequency response of the amps as a basis for comparison?

This could be done using a function generator, sweeping a constant-amplitude sine wave through the audio spectrum and measuring the signal amplitude with a scope at the output of the amp.

A man was leaving a convenience store with his espresso when he

noticed a most unusual Italian funeral procession approaching the nearby

cemetery.

A black hearse was followed by a second black hearse about 50 feet behind

the first one. Behind the second hearse was a solitary Italian man walking a

dog on a leash.

Behind him, a short distance back, were about 200 men walking in single

file.

The man couldn't stand the curiosity.

He respectfully approached the Italian man walking the dog and said: "I am

so sorry for your loss, and this may be a bad time to disturb you, but I've

never seen an Italian funeral like this. Whose funeral is it?"

"My wife's."

''What happened to her?"

"She yelled at me and my dog attacked and killed her."

He inquired further, "But who is in the second hearse?"

My mother-in-law. She came to help my wife and the dog turned on her and

killed her also.

A very poignant and touching moment of brotherhood and

silence passed between the two men..

The man then asked "Can I borrow the dog?"

The Italian man replied, "Get in line."

Hello, and welcome to the site!

You said that you measured the supply voltages per the photo I posted in the other thread. Could you share both the DC and AC measurements? These measurements are taken at the rectifier diodes because they are the most convenient point at which to probe.

Thanks!

Les