[R-390] R-392

[John Bunting]

Roy,

Thanks for the good information.  I have a small postal scale that I use to 
weigh ink cartridges that I'll use. It has 1/2 Oz calibrations and I can 
interpolate between those for a better idea of the before and after weights. 
The R-392 has a nice vent hole in the front panel just below the center of 
the dial window assembly.  The plug has a neoprene "O" ring around it and I 
used it to get excess moisture out after a 48hour run early on.  I've always 
figured that was what it was intended for.  The size of the hole looks to be 
around 1/4".

73, John, W4NET
----- Original Message ----- 
From: "Roy Morgan" <roy.morgan at nist.gov>


> At 08:36 PM 10/10/2005, John Bunting wrote
> :... have four packages of Silica-Gel, two cloth ones with 15 grams each 
> and two larger paper ones with about one ounce each.
>
> John,
>
> (This is based on limited experience with silica gel):
>
> A dried out pack of silica gel will absorb maybe one third it's weight in 
> water.  It's unlikely that an R-392 contains more than an ounce or two of 
> water in the air inside, even if warm and saturated.  But:
>
> 1) If you dry out your silaca gel packs, weight them, put them back in the 
> radio and the weight goes up by maybe a third or half, then they can't 
> glom any more water.  ("Glom" is a technical term used by a jeweler while 
> we were an buying engagement ring about a year ago: "Don't glom the 
> stone!" I was sternly advised.)
>
> 2) If the radio shows condensation inside the window, especially upon 
> cooling, then there's moisture inside there.  Good idea to get it out. 
> Though I don't own an R-392 (yet), here is my suggested procedure:
>  - wait till a dry day arrives
>  - Run the radio till quite warm, and crack the case so it ventilates.
>  - close the case nicely to keep the dry air inside.
>
> 3) If (when) I have an R-392, I will tuck inside there somewhere an 
> 8-ounce pack of silica gel from among the few I've collected. (They were 
> found in helicopter transmission and engine packing cans during my time in 
> the Navy.)  I'm assuming that room for such a pack can be found in there 
> somewhere.  About the size of a large pack of M and M's.
>
> 4) To de-water, place in any oven, kitchen- or toaster- at 220 to 250 (low 
> to medium "WARM" on the dial) for a couple hours.. then allow to cool off 
> with the oven. If you weigh your packs before and after de-watering, you 
> will know how much water they can absorb.
>
>>  I've heard about putting them in a cookie tin or something and low 
>> temperature baking them for ??
>
> The cookie tin won't keep in much moisture with heat but I would not put 
> them in any tin.. just in the oven. You are baking the water OUT, not 
> trying to keep it in.  Plastic bags, maybe two layers, server as storage 
> after drying.
>
> Roy