Contact Cleaner 'type' (on Tivoli radio)

[GreenCDN]

Hi all,

I just bought an old but brand new Tivoli 'Model One' radio (platinum series - yay!). I suspect this thing is near 20 years old. Stations come in and play clearly, but... while I'm still dialing in a station, the audio output can be quite scratchy/noisy. The volume knob works flawlessly, though.

So, the most common solution, I've read, is take out the back screws and pop-out the front panel and give the station-dial a cleanse. And while I'm doing that, I may as well do the same for the volume and input selector knobs.

I'm not an electronics type of guy, but I think the volume (and input selector?) are known as pentiometers... but not the station-dial, which I think is called a 'varicon'. Someone - please correct me if need be. The varicon seems to be all metal sheets... though, has a dialectic element to it, from what I can tell. There's a Youtube video showing the Tivoli varicon, here:

In any case, at home, I have some DeoxIT D100 and DeoxIT Gold contact cleaner spray.

Question: Is the D100 okay to use to clean and lube the varicon, or do I need to buy and use some D5, or completely change over to the DeoxIT Fader line and get the F5 or F100 solution (better for metal on plastic)? And would the same spray be fine to use on the volume & input selector knobs?

Thanks!

 

[swechsler]

Instructions here for cleaning an analog tuner.

 

[daybreak2350]

CRC QD Electronics Cleaner works for me, 11 oz. spray can around ten dollars, commonly found in hardware and auto parts stores, should have small red tubing (like a very small diameter straw) taped to side of can--you insert it into the nozzle, made to direct spray into tight spaces, push-on and Molex connectors, and inside the "can" enclosing a "pot" which is usually the part needing rejuvenating, leaves no residue.
Your questions are pretty basic but you seem to be willing to learn, gotta crawl before ya walk. Here's my input:
If your radio is in new condition then it should not be dirty inside but it wouldn't hurt to give it a general light cleaning (vacuuming etc.) as in swechsler's link above just in case slight oxidation has formed on contacting parts. However, from what you describe my guess is that the radio's electronics probably need little or no cleaning. Or, a telescoping or solid whip antenna attached to the plug.
Terminology:
What you call pentiometer is actually a potentiometer (or "pot"), typically for volume and tone controls. which is in itself a variable resistor enclosed in a flat round "can" with two protruding connector tabs to attach (solder) wires; a short treaded neck fits through a hole in the front panel and is held in place by a retaining nut which will be hidden when you put a knob on the shaft. Inside the pot is a wiper (flat metal tab) attached to the shaft that rotates when you turn the knob attached to the end; when rotated, the wiper sweeps across a length of wire wound around a circular crescent-shaped non-conductive coil form (not to be confused with a transformer coil). To clean a pot, you should try to direct the cleaning spray inside the can enclosure if there's an opening.
Varicon: I believe this is a portmanteau blending Variable with Condenser (old term for capacitor); this is the part with the interleafing metal plates--the tuning capacitor-- which you can spray to remove any dirt or oxidization but probably not needed for a part in new condition. It is important not to bend these plates as the plates must not touch or it would short the tuning capacitor. Being in new condition, I doubt it is necessary to apply a lubricant on the shaft bushing and you don't want oil on conductive parts.
Input Selector is a rotary switch, not a pot.
Scratchy audio: My guess is that the scratchy "white noise" you hear is actually static from the airwave signal itself as you tune through the AM band. On the other hand, if you were hearing scratchy noise when turning the volume control it would indicate a dirty pot which should be spray cleaned.
External antenna: One of the jacks on the rear panel is for attaching an external antenna, which would increase the signal strength and "pull in" weaker stations but probably not get rid of the static white noise. The jack appears to take a 1/8-inch phono plug. To make an external antenna you would solder a long length (like 10+ feet--the longer the antenna the stronger the signals received) of small gauge (e.g., 20 or 22 ga.) wire to the plug's center connector, plug it in, and string the wire out overhead.

Good luck, happy listening!

 

[ecluser]

Don't inject any contact cleaner inside a variable capacitor that has dielectric film between plates, even it it says "safe for most plastics". You will ruin your variable capacitor.

 

[WizardWG4]

I used to have one and the easiest thing to try first with these Tivoli radios is move the tuning dial back and forth end to end repeatedly for several minutes.

If that doesn't work you can try the more extreme measures.

 

[John James]

What he said.

 

[macyjrm]

To piggyback on what Wizard says above, turn the radio upside down while exercising the tuning dial through its full range. IIRC these models were built with a special grease which gravity pulls away from the mechanism. The upside down trick has worked very well for me and my two Tivoli units. Those cabinets weren’t built for easy access or maintenance.

 

[daybreak2350]

Don't inject any contact cleaner inside a variable capacitor that has dielectric film between plates, even it it says "safe for most plastics". You will ruin your variable capacitor.

You're absolutely right although mica might possibly be an exception. IDK what the varicon uses. I should have paid closer attention to bwack's video. I was thinking of the air-as-dielectric variety (a picture of which he inserts for reference) as used in vintage radios. Thanks for pointing this out.

 

[GreenCDN]

I appreciate all the feedback!

Swechsler... The video was a little over my head, as it is referencing things I'm not particularly familiar with.
Daybreak... The definitions & advise were helpful, thanks! The scratchiness was fixable - see below. Also, I've been using an external antennae from the beginning.
Daybreak & Ecluser... noted - I should not spray any contact cleaner at any time into the varicon, where I've been having issues. Very good to know!
Wizard & Macyjrm... yup yup! Took more than a few turns of the dial, but yup!

I'd only read Swelchsler's response before a helpful Tivoli customer service rep suggested I unplug the unit and leave it sitting upside-down for 4 hours, then flip it right-side-up, plug it in (i'm guessing to warm it up a bit), turn the volume down to nil, and slowly turn the dial back and forth across the whole range for 5 minutes. Well... after turning the dial for half an hour, there was a LOT of improvement when I tested it... and after more than a full hour of turning the dial (all while watching a movie), it was PERFECT. All loud static/scratchy noise gone! This thing thing looks great, and works great too, now.

In my setup, I've got the Model One (rec) outputting to my main amp & speakers... but it's own mono-speaker works fine too.

Thanks for all the great advice!

 

[KeninDC]

FWIW, I have a Tivoli Model One. About once a year I open it up and spray all the moving parts willy nilly with Deoxit D5. Bye-bye scratchy tuning.

In other words, don't overthink this.

 

[daybreak2350]

I appreciate all the feedback!

Swechsler... The video was a little over my head, as it is referencing things I'm not particularly familiar with.
Daybreak... The definitions & advise were helpful, thanks! The scratchiness was fixable - see below. Also, I've been using an external antennae from the beginning.
Daybreak & Ecluser... noted - I should not spray any contact cleaner at any time into the varicon, where I've been having issues. Very good to know!
Wizard & Macyjrm... yup yup! Took more than a few turns of the dial, but yup!

I'd only read Swelchsler's response before a helpful Tivoli customer service rep suggested I unplug the unit and leave it sitting upside-down for 4 hours, then flip it right-side-up, plug it in (i'm guessing to warm it up a bit), turn the volume down to nil, and slowly turn the dial back and forth across the whole range for 5 minutes. Well... after turning the dial for half an hour, there was a LOT of improvement when I tested it... and after more than a full hour of turning the dial (all while watching a movie), it was PERFECT. All loud static/scratchy noise gone! This thing thing looks great, and works great too, now.

In my setup, I've got the Model One (rec) outputting to my main amp & speakers... but it's own mono-speaker works fine too.

Thanks for all the great advice!

One good turn deserves another, right?
So fortunate to have that level of "customer care", very impressive in this day and age. Upside down, 'eh?--a lot easier than putting it in a centrifuge, for sure.