[time-nuts] time-nuts Digest, Vol 79, Issue 31

[gonzo .]

Thanks for the comments and suggestions.

I've dropped the heatsink temp to 69C simply by swapping the side panels (a small step in the right direction).

The internal fan makes a fair howl, so a small fan or two will hardly be noticed! The original fan is moving plenty or air, but it's sounding like the bearing is past it's prime. 
I'll replace it as soon as I can find something suitable (110V fans are a bit thin on the ground around here).

Cheers,
Ian

> ------------------------------
> 
> From: paul swed <paulswedb at gmail.com>
> Subject: Re: [time-nuts] HP 5370A temp
> 
> Yup various components have been run hot.
> Like others in this group add a fan to the heat sink. Found a way to route a
> wire out from the raw 5 volt supply to run a 12 volt fan. Think I took one
> bolt out of the heat sink to route the wire. Think I added a resistor as I
> did not need a lot of air to calm the heat sink down.
> 
> Definitely consider changing really stressed components they can be a bit
> brown and still be OK. Measure them.
> Good luck
> Regards
> Paul
> WB8TSL
> 
> 
> ------------------------------
> 
> From: "Don Latham" <djl at montana.com>
> Subject: Re: [time-nuts] HP 5370A temp
> To: "Discussion of precise time and frequency measurement"
> 
> My 5370a's both run hot as heck. I used some cheap small c-clamps and some
> old heatsinks to increase the area of the hp heatsinks. You can also run
> an old fan if you have one. I've found that the whole era of Hp equipment
> runs too darn hot. 3325a, 8656a, etc. etc.
> Don
> 
> 
> 
> -- 
> "Neither the voice of authority nor the weight of reason and argument are
> as significant as experiment, for thence comes quiet to the mind."
> R. Bacon
> "If you don't know what it is, don't poke it."
> Ghost in the Shell
> 
> 
> Dr. Don Latham AJ7LL
> Six Mile Systems LLP
> 17850 Six Mile Road
> POB 134
> Huson, MT, 59846
> VOX 406-626-4304
> www.lightningforensics.com
> www.sixmilesystems.com
> 
> 
> 
> 
> ------------------------------
> 
> From: "Bob Camp" <lists at rtty.us>
> Subject: Re: [time-nuts] HP 5370A temp
> To: "'Discussion of precise time and frequency measurement'"

> 
> Hi
> 
> Gee, a low cost 5370.... 
> 
> The nice thing is that even though it runs hot - it's done it for a *long*
> time. I certainly would not argue against a fan. They are a *very* good
> idea.  However it's not going to turn to dust without one.
> 
> I would definitely keep it clean and keep the back side open to air. As you
> have noted - make sure the vent holes are where they should be and
> unblocked. Stacking 5 or 10 on top of each other likely isn't a good idea
> either ....
> 
> Bob 
> 
> ------------------------------
>From: "gbusg" <gbusg at comcast.net>
>Subject: Re: [time-nuts] HP 5370A temp
>To: "Discussion of precise time and frequency measurement"
>
>I think 61?C might be more typical, so 76?C seems pretty darn hot to me. I 
>would make sure that your fan is running, and is mounted the right 
>direction. (It should be blowing *into* the instrument.)
> 
>Also make sure that the top instrument cover is installed. (The top cover 
>must be in place so that the internal fan air currents will loop around and 
>pass through vents, including the through-holes in the rear heat sink.)
> 
>Greg