Cleaning smoker's tar off an HT-33A

[KB2FCV]

I have an HT-33A Linear that I acquired a while ago and I'm finally able to get around to cleaning up this amp and to start testing it out. At some point in this amplifier's life it lived with a smoker and as a result has some yellowing. What should I use to clean it and what kind of rag/cloth should I use that will protect the paint?

[KB4QAA]

Recently I've settled on Krud-Kutter, which I get at Lowes hardware.

It works incredibly well, but is gentler than anything else I've tried. It is quite strong and can be diluted for economy, for situations that aren't as dirty and in order to be more conservative in restoration.

I use a chip brush, tooth brush and a nail brush, and keep a bowl of water handy for dipping the brushes in, while working by the sink. You need to use plenty of water to rinse it clean.

Krud Kutter doesn't have a heavy perfume and is supposed to be 'all natural'.

Bill

[KB2FCV]

Bill,

Many thanks for the suggestion. Actually we have Krud-Kutter as one of our cleaning supplies. I was not aware you could use it on radios. I'll give that a shot, thank you!

73,

James

[WD0GOF]

I have an HT-33A Linear that I acquired a while ago and I'm finally able to get around to cleaning up this amp and to start testing it out. At some point in this amplifier's life it lived with a smoker and as a result has some yellowing. What should I use to clean it and what kind of rag/cloth should I use that will protect the paint?

CLEANING
Step 1. I have found all forms of foreign matter in rigs emerging from long term storage. My favorite of cleaning method is the bathtub, Scrubbing Bubbles bathroom cleaner, and the shower hand wand. I set the rig in the tub, back side down, front panel up. With the rig leaning against the side of the tub I spray it full of Scrubbing Bubbles and let it set 3 to 5 minutes. Then I spray it full again and after 5 minutes I rinse it using the shower hand wand. I do this on the top and bottom side of the chassis. I keep the Scrubbing Bubbles away from the front panel, dials and meters, just use common sense. All the brown residue, smoke odor and filth literally runs down the drain. Very seldom is any scrubbing needed if it is I do it with a ¾” wide paint brush with half the length of the bristles cut off. I rinse it a second time then it sets in front of a fan for a day.

Step 2. Now that it is squeaky clean the potentiometers need the application of a suitable control cleaner/lubricant.

Step 3. Some mechanical drive trains to tuning devices require special lube so don’t forget them.

Step 4. The relays are next. I use thin strips of card paper, about 3” long and 3/16” wide. Place a drop of DeOxit on the paper and slide it back and forth between the contacts. Manually energize the relay and clean the normally open contacts as well. A pair of hemostats simplifies this step. NEVER USE SANDPAPER.

Step 5. Now for the controversy, The Wafer Switches! Every three months or so on one of the ham forums a wafer switch cleaning war breaks out. No minds are changed, no territory is conquered. Hostilities subside only to be resurrected a few months later when the “new be” asks How do I clean my wafers. There are at least 3 regulars out there that vehemently oppose my method and that is ok. It works for me and I have not to date suffered any loss due to it. First I take a cotton swab and cut a little cotton off the tip. I spray a little DeOxit in a small glass bowl. I dip the swab in the DeOxit and clean the switch. Pretty simple and no over spray. I NEVER spray DeOxit into a rig.

Step 6. Now to clean the tube sockets. Some where around the tooth brushes at you local store you will find very small round brushes used to clean between teeth. There are usually 10 or 20 to a package. Once again I use DeOxit in the glass bowl. Dip the brush, insert the brush, spin the brush, repeat 150 times or so and you’re done.

73, Walt

http://www.myhamshack.com/WD0GOF/

[KB4QAA]

Walt, I have to agree with you about DeOxit and wafer switches. Last winter I sprayed the main switch on my NC-173, and the phenolic material swelled up and became very difficult to turn. The only thing that has helped is waiting for it to evaporate.

For tube sockets I use a "real" pipe cleaners soaked in Deoxit. I had to hunt around to find a drug store that had a big tobacco section. The pipe cleaners they sell in craft stores are plastic, disintegrate and are worthless. As a section becomes soiled, I use my nippers to clip it off and expose the clean area.

The only tooth cleaners with brushes I have found have all been plastic. One tip I read several years ago suggested using a mascara brush. *I haven't had the nerve to buy mascara just to get a brush* LOL.

[WD0GOF]

Walt, I have to agree with you about DeOxit and wafer switches. Last winter I sprayed the main switch on my NC-173, and the phenolic material swelled up and became very difficult to turn. The only thing that has helped is waiting for it to evaporate.

For tube sockets I use a "real" pipe cleaners soaked in Deoxit. I had to hunt around to find a drug store that had a big tobacco section. The pipe cleaners they sell in craft stores are plastic, disintegrate and are worthless. As a section becomes soiled, I use my nippers to clip it off and expose the clean area.

The only tooth cleaners with brushes I have found have all been plastic. One tip I read several years ago suggested using a mascara brush. *I haven't had the nerve to buy mascara just to get a brush* LOL.

The brand name for the ones I use is "DenTek DUAL ACTION". They are twisted wire with individual bristles. I have tried the plastic ones and they do not work for me. I to have used real pipe stem cleaners and still use them on The larger octal pins. The heavy duty pipe cleaners that have stiff plastic or metal bristles laced throughout work well. My only gripe with the pipe cleaners is that they sometimes leave behing cotton fibers.

73, Walt

[K9STH]

FCV:

How's your back! :rolleyes:

Lifting the HT-33 series is not a task that I relish! Not quite as bad as a WRL Globe Champion 350A but still bad enough!

You might check the circuitry in your HT-33A. The last "run" of HT-33A linear amplifiers were actually the same as the HT-33B. That is more voltage regulators than the "normal" HT-33A. The HT-33A that I obtained about a year ago (which I still have to get restored!) has all of the upgrades, done at the factory, as the HT-33B but it is definitely marked as an HT-33A.

Glen, K9STH

[WA9CWX]

In direct comment to the smoke residue. I have tried everything, twice. depending on the surface and the needed self limiting care in the use of pressure. my best success has been with ammonia, full strength, soaked for a long time, then rubbed with force. obviously not practical on much of the face, or over any lettering.....Best of luck, it ain't an easy trip.
One TR4C took me a week. One Vibroplex took me 8 straight hours, just for smoke removal.

Frank