Ever since ive had this radio, it sends a loud "crack!" to the speaker on and off when its on.

Turning the volume up or down dosent effect the loudness of the "crack"

I took it to a repair man and he recapped it and fixed the crackling knobs.

He said I need new valves and that one of the valves that he tested, failed the test and is "bad"

So after money spent, the cracking is still there, so do you guys think replacing the valves and especially the "bad" valve, will stop the crackling?

Thanks!

95 percent sure it will. can you tell us how much he charged for the repairs.

Hey folks

well I'm disappointed to say the least

ive spent over $200 on this radio to get it working properly and after everything, its still make a loud "cracking" sound.

ive got the electronics man who is registered, and has a business in this town, to clean the scratchy pots, replace all the caps, and I installed

brand new valves.

I got the valves off the net from a legit site and put them in. the tech said hes not going to be in town much anymore

so I cant take it back to him

anyone know whats happening with this radio?

thanks guys

Did you clean the valve sockets at all. That can be a cause.

Dirty valve sockets and resistors going high are probably the most common causes of this. I'd be checking valve sockets first, starting with the output valve and working back to the rectifier as this is cheaper than replacing resistors that may not need replacing.

I'd try replacing the 100pf mica capacitor from the 6BD7 anode to chassis (assuming it's there).

Or, disconnect it first to see if it is the problem. If the crackles are gone then replace it.



Wonder what the $200 paid for...

Jaycar sell a very good contact cleaner . All you need to do is pull the valve out and spray the sockets and then put the valve back in and out couple of times. Do this to all. these sort of problems are usually very simple problems but you need to know where to look. One similar problem I had was a dirty volume switch . What I did to fix it was to loosen the switch of the chassis a bit and then sprayed wd40 into the internals then I tightened the switch back up and hey presto the problem was no longer.

Cost me 100 bucks to get it recapped, pots cleaned, and a led light fitted

cost me another 100 bucks for the new valves

cost 140 bucks to buy the radio of ebay

also, whats the best contact cleaner to use?

thanks guys, much appreciated

The one I use is the jaycar brand. but the others may know something good. Does the cracking noise happen by itself or when you use the knobs.

I'd try replacing the 100pf mica capacitor that Robbert suggested.

There are a few common things that cause that effect and one thing to do is note its frequency. If it is regular something is building up to a point & flashing over. That actually can be any cap including the filters but is more the realm of a Silver Mica type with lots of volts on it.

I would suspect it's after the volume control in the audio, as the volume seems ineffective. A circuit, if available would be useful. The other flash over common to the audio is where either the loudspeaker secondary goes open and / or the voice coil becomes detached causing an open circuit (bad soldering / no soldering (seen it)). Invariably that causes the transformer to "ring" like an ignition coil & there is a flash over, often across the OP valve pins.

Do check for bad solder joints, prodding with a plastic chopstick is good.

Unfortunately you do get the Cowboys. I have a car radio here that came with a receipt for $300: Absolute ripoff. I estimate at least 2-3hrs to put it right.

Marc