[R-390] Hammond Cabinets

[Roy Morgan]

On Nov 23, 2010, at 3:17 PM, James Young wrote:

> .... I don't know, and
> have wondered myself, if the CY-979/URR is an appropriate cabinet  
> also for
> an R-390 or R-391. Any ideas?

Here's my idea:

NO ONE should run an R-390/URR (the "non-A") without a fan.

I made a metal plate to mount a 4 inch square computer fan against the  
side of the radio using the existing screws: two frame screws and two  
bottom cover screws.  I have a picture of the somewhat crudely made  
plate including a ruler to other folks could make one too.  'Glad to  
send the picture to any who are interested.  OR: maybe some one could  
post the thing with my comments on some web site.

In rack mount and cabinet installations, the fan needs to be mounted  
after the radio is in place.  (Does the CY-979 have a lift-up-top?  
Maybe not.)  Cut-out slots for the screws make this do-able if you can  
get the the side of the radio from the top, bottom, or rear.

- A Thin fan might slip past the rack or cabinet rail.
- A fan inside the frame would be better.
- Modest air flow can cool the B+ regulator tubes from literally  
blistering hot to touchable.
- A capacitor in an AC fan power line can slow it down.
- A 12 volt DC fan run on rectified filament power (6.3 volts, not  
found in the non-A) runs quiet and does not need to be switched on/off.

Roy

Roy Morgan
k1lky at earthlink.net
K1LKY Since 1958 - Keep 'em Glowing!