Substitute parts for model Twenty One

[JeffS]

JKent,

I'm hoping you can help me here. I acquired my first model twenty one in September and restored it last month. I'm very pleased with it, so much so that I found another at an estate sale last week and grabbed it. When I was removing the large portion of the tuning knob I broke it into four pieces. I thought of trying to piece it back together but then found that there is a model twenty AM/FM phono unit in need of repair for sale locally and the tuning knobs look to be identical. Do you know if this is true or are there differences in the inserts that fit over the shaft.

Jeff S.

[JKent]

Hi Jeff

The before & after looks great! Those plastic grilles are a pain. How did you deal with the shrinkage?

I'm afraid I don't know the answer to your question. It does seem logical. Maybe you can let us know what you discover.

If you want to try repairing the original, Plas-T-Pair should work.

-Kent

[ra.ra]

Totally agree with Kent - - nice-looking restoration on that radio. While I suppose it is possible that the model twenty may have been released with more than one version of styling and details, the only version I am familiar with has a very different looking knob than what's shown on your radio. Not only do the "twenty" knobs have silver caps, they also have the printed station tuning numbers on the knob itself rather than on the face plate, and that is not what you are looking for.

[JeffS]

Kent and ra.ra,

Thanks for the compliments on the restoration. I thought it came out pretty well for my first try. All the electrolytics were replaced though I'm thinking of going back in to see if the tuning capacitor could use some cleaning.

I started cleaning the grill using a a bleach solution and applying it with a toothbrush but didn't want to get the masonite too wet, let alone the speaker, so I dismantled the unit and removed the cloth from the front board. Soaking it in a bleach solution for an afternoon cleaned it nicely. To 'stretch' the grill I simply moved it about 1/8" to the left before gluing it back down. There is just enough extra material on the right side to allow it. I'm thinking that the grill material is saran since it behaves like an AR-3 grill. An extra 1/8' of width on the grill would come in handy though it's certain no one at KLH ever thought it would be an issue, let alone in 2015!

As for the model twenty, it appears that, just like the twenty one, there are a few variants. The one that is available to me has what looks to be the same knobs as the 1st generation model twenty one. I'm guessing they are a fit unless the insert is different. And if they do fit then I'll have another spare as long as I don't break it.

[ra.ra]

Yup, slight variations within the same model number do abound, and it appears you may have indeed found a source for a replacement knob; but then you will soon find yourself in need of yet another replacement knob to fit-out your newly scavenged model twenty!

[JKent]

Yup, slight variations within the same model number do abound,

...and sometimes not so slight. As many here know, KLH made FIVE different "Model Twenty-One" radios: The Twenty-One, Twenty-One/II, Twenty-One FM, Twenty-One AM/FM and the Twenty-One CL (clock radio). The model number was always spelled out.

Here are four of them. The AM/FM is missing but looked just like the FM with the addition of an AM scale.

The 21/II was Singer-era and quite nice. My tech thinks it (and the late 21s) were superior to the original.

Each had its own "issues":

• The original 21's vinyl (?) grille tended to shrink with age
• The 21/II had a slightly cheaper cabinet. It was walnut veneer over particle board (instead of plywood) and the particle board is fragile and crumbly. The black cloth grille tends to fade to brown, the "acoustic suspension speaker" badge is often missing and the aluminum caps on the knobs fall off.
• The FM, AM/FM and CL were all good radios but had the abominable "wood-grain vinyl" covered cabinets. They also had foam grilles that of course deteriorate with time and make it even more likely for the AS Speaker badge to get lost
• The clock radio was a disaster. My tech says he used to buy replacement clock movements by the case. A working one is a rarity. But it still sounds good.

I've restored all of the versions and my favorite is the 21/II. It's easy enough to re-stain the grille cloth and if the cabinet is beyond repair you can just use one from an original 21 donor.

-Kent

[JeffS]

I finally acquired the Model Twenty that was advertised on Craigslist three weeks ago. Just as I had hoped, the tuning knobs are exactly the same as what is used on the Model Twenty-One. The seller had this stored in an outbuilding for some time and didn't have the speakers so this works out perfectly as I would be tempted to restore it if it was complete. Out of curiosity I connected a dipole antenna and the stereo light / tuning meter jumped to life, responding to quite a few local stations. I'll have to make an RCA speaker connector so that I can give it a listen.

JKent, do you reseal the surround when you restore a Twenty-One? The unit I have open now seems to pass air pretty easily, and the unit I restored sounds a bit bass shy (I didn't reseal that surround). Also, have you seen both lacquered and oiled cabinets in the units you've restored?

Jeff

[JKent]

Hi Jeff

Good luck with your project.

I don't routinely re-seal the 4" drivers although KLH DID recommend it. If you go that route be sure to use Roy's sealant ONLY.

There are other potential air leaks: The RCA jacks should be capped. You can use screw caps from a hardware store. They're color coded and the correct ones are green. There is also an ebay seller in China who has black ones--see eBay item number: 191259779850.

Also replace the foam gasket on the back, around the perimeter and around the opening where the various jacks are. The photo below shows new perimeter gasket (1/8" x 1/4" weatherstripping), black gasket around the connections (PE woofer gasket works if you have some) and the green caps.

I'm not an expert on Model Twenty-One finishes but I *believe* they were oiled. I usually use Howard Restore-a-Finish followed by Minwax Antique Oil, which contains some varnish and gives a harder, glossier finish than Watco Oil.

-Kent