[SBE] RCA Dummy Load

[DanRapak at verizon.net]

Gibson, Clay,

Thank you both for the fast replies!

Yes, it does have an "N" connector and it does buzz out at 50 ohms as 
expected. I know this one was used at a VHF TV station back in the day.

O.K. on the temperature sensor. Do you know if that's an On/Off function 
or a sensor of some sort?

I believe there was some magical RCA oil. My recollection is that stuff 
smelled awful and if you got it on your clothes you might as well throw 
them out because you never got the oil or the smell out of the material. 
I might even have some around here somewhere, but I'm not sure what the 
shelf life would be for something like that. I'll check into the Bird 
oil and failing that, I'll fall back to plain old mineral oil.

Dan


On 4/5/2018 9:27 PM, Gibson Prichard wrote:
> Dan,
> Most dummy loads are 50-ohms across a wide frequency band, so 
> frequency shouldn't matter too awful much. What is the connector on 
> it? If it's a SO-259, Type-N, or an EIA flange of some variety, does 
> it test as 50-ohms?
> The two-pin connector could have been a temperature sensor so that it 
> could act as an interlock and cutoff the transmitter if it overheated 
> to keep from damaging the load or the transmitter.
> Most oil-filled loads use something like a light mineral oil, although 
> I'm sure back in the day there was a specific RCA-branded oil to fill 
> it with. Unless you intend to run it near its peak capabilities, I 
> doubt the exact variety of oil will matter, Here is a page from eHam 
> about this very topic - 
> https://www.eham.net/ehamforum/smf/index.php?topic=70579.0;wap2
>
> Gibson Prichard
> Nashville, TN
> gibson at prichard.tv <mailto:gibson at prichard.tv>
>
> On Thu, Apr 5, 2018 at 8:02 PM, <DanRapak at verizon.net 
> <mailto:DanRapak at verizon.net>> wrote:
> >
> > All:
> >
> > I'm looking for information on an old dummy load. I have an old RCA 
> liquid cooled dummy load that's been collecting dust for several 
> years. It is an RCA  P/N 216251. It's a nice unit with substantial 
> heat fins. It's rated at 1 KW continuous and 1.5 KW for 30 minutes. 
> I'm about to put it in service in the ham shack. However, I have no 
> manual for it.
> >
> > My first question is, does anyone know what the frequency range of 
> this unit is?
> >
> > Second, there is a two-pin, military style Amphenol connector on the 
> the dummy load. What is the purpose of this connection?
> >
> > Finally, what is the recommended transformer oil / coolant for this 
> thing?
> >
> > Any help would be appreciated.
> >
> > Thanks in advance,
> > Dan Rapak
>
>
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