Restoring a radio - need advice

[Yuri D.]

Folks,

I'm restoring a T8PL39 receiver. It is almost identical internally to an Lw.E.a, except for the frequencies and direction-finding gear. I have several questions:

1. Metal screens around the stages: what is a good metal-colored paint to use on these surfaces?

2. Mechanics: What is the best way to a) clean the mechanics, and b) what is the best lubricant to use on them.

I have already used silicon spray on the zinkpest, and that worked very well to eliminate the zinkpest and stop further corrosion on the surfaces.

Yuri

[Val]

1. Metal screens around the stages: what is a good metal-colored paint to use on these surfaces?

2. Mechanics: What is the best way to a) clean the mechanics, and b) what is the best lubricant to use on them.

I have already used silicon spray on the zinkpest, and that worked very well to eliminate the zinkpest and stop further corrosion on the surfaces.

Nice beast "Martin" you have there.

http://www.cdvandt.org/t8pl39.htm

1. There's several aluminum based paint available. Try some of them on some non-important piece.

2. Do you mean like just clean or clean from rust?

[Yuri D.]

I will try to just sand down the rust on the steel using very fine 1500-2000 grain sand paper.

The gears in the mechanics are in good condition, but I will need to clean them from the old grease and apply new grease. How to clean? Which grease to use?

Also, one of the steel gears has surface rust on it. How do I gently clean that off?

Thank you,

Yuri

[Yuri D.]

Nice beast "Martin" you have there.

http://www.cdvandt.org/t8pl39.htm

1. There's several aluminum based paint available. Try some of them on some non-important piece.

2. Do you mean like just clean or clean from rust?

Calling it a "beast" is fitting. It weighs 68 KG. The metal housing alone is 1/3 of that. It will be a bit of a restoration job, as some of the surfaces are oxidized, but nothing too bad. It will look great when I'm done - with original paint and all.

Yuri

[hcs]

Sounds like an interesting restauration job, how about some pictures?

[hcs]

I will try to just sand down the rust on the steel using very fine 1500-2000 grain sand paper.

The gears in the mechanics are in good condition, but I will need to clean them from the old grease and apply new grease. How to clean? Which grease to use?

Also, one of the steel gears has surface rust on it. How do I gently clean that off?

Thank you,

Yuri

If the gears have been dismounted from the radio, I would remove old grease with kerosine and a brush, I would grease with acid free grease, maybe molykote, I have it from a gun shop, so I guess it is safe to use on gears too.
I would soak the rusty gears in WD40, for some time and use a stiff brush to help it on the way now and then.

[Val]

I will try to just sand down the rust on the steel using very fine 1500-2000 grain sand paper.

The gears in the mechanics are in good condition, but I will need to clean them from the old grease and apply new grease. How to clean? Which grease to use?

For removing old grease from the metallic parts i have used the medical spirit or benzine/gasoline, only later i have still used spirit to clean off any possible benzine traces. Let gear stay some time in spirit/benzine and then use small brush.

What grease to use is much harder question and probably device dependent - what viscosity grease was used there before, gear speed, gear material etc. How often there's in original manuals stated what grease to use?

[Tornfuté]

yuri i search in my book NVK-GB/39 of telefunken , i don't see any reference to grease . i clean old grease with" tricloretylene " writting ? about molykotte
grease i remember they use it on ship , there is some grafite added , and it's suitable to use on warm parts ., it will lubricate gears perfectly i believe
in the book they says that the T8 PL39 is 62,7 kg , t8pl39 = E491 N
if you need an inside picture , i have 2 sets so no problems .
pierre

[Yuri D.]

yuri i search in my book NVK-GB/39 of telefunken , i don't see any reference to grease . i clean old grease with" tricloretylene " writting ? about molykotte
grease i remember they use it on ship , there is some grafite added , and it's suitable to use on warm parts ., it will lubricate gears perfectly i believe
in the book they says that the T8 PL39 is 62,7 kg , t8pl39 = E491 N
if you need an inside picture , i have 2 sets so no problems .
pierre

Pierre,

Thank you for the information.....did you say you have two receivers?

Yuri

[Tornfuté]

hello yuri
the answer is yes , i have 2 , that's the same for broadcast E381
also E509 of Lorenz , a beautiful receiver far more well made then the
telefunken . i also have the SPEZ801 also a marine beast of around
65 kg , or more a nice receiver one of the best of his time .
some people like feldfu ;or other , for me as old seamen , i like the
marine receivers , i only have one Wupper and one Main, they are
developped beffore the E52 but same way , with optical engraved
scale . in tx i have the uboat S406 transmitter .
regards pierre

[Val]

Here what is suggested to use in case of your H.E.1, Yuri - knochenöl.

[Funksammler]

I typically use WD40 to clean off any surface rust, it also helps to dissolve any old grease. Hardened grease may need some stronger solvents like thinner. A piece of cloth, a hard brush, cotton buds, wooden toothpicks and a lot of elbow grease usually do the trick. For more stubborn corrosion I use a small rotary brush in my Dremel. Depending on material you work on you can use different brushes (plastic, copper or steel). If necessary surfaces can be polished with some 1200 gauge waterproof sandpaper and a bit of oil.

I do not think the type of grease you use is that critical, there is hardly any load or heat going into the bearings, so any bearing grease will do. Old grease can sometimes be "rejuvenated" by applying some thin oil like WD40. Grease is essentially oil packed in a fibrous matrix, with time the light hydrocarbon elements in the oil evaporate, so a recharge with light oil can sometimes help.

I make a habit of "cleaning" my equipment with a slightly oily rag from time to time. Not only does it remove dust, but it keeps the paint in good condition and keeps surface rust under control. Use a slightly heavier oil, as light oil such as WD40 can sometimes impact on ink quality control or waffenamt stamps.

As for repainting some or the internal bits, the Germans often used silver or light grey paint on internal metal parts. A spray-can of car paint will do the job, they usually have a shade that comes reasonably close. Hammerite can be used directly on corroded surfaces (make sure they are fat free though) and will protect the surfaces long term.

If the corrosion is not too bad, I prefer to leave it in place, just controlling it with some oil. It gives the equipment a bit of character!

regards,

Funksammler

[Yuri D.]

The receiver from the front side:

[Yuri D.]

Reverse with cover off:

[Yuri D.]

Detail of IF and LF stage block: