If they're only rated for a few seconds (yeah, they are), then the difference
between transformer and mineral oil is probably measured in milliseconds - not
enough to bother. The thermodynamics of a paint can are really not up to the
application. Unless you're building or servicing amplifiers on a regular
basis, there isn’t much more than a few seconds of need for full power into a
dummy load on an occasional basis anyway. If you really need more, buy or make
a real DL. If you're tuning into a DL (I hear some hams do this), why? I use
the Cantenna when an amp is on the bench, which isn’t often. Otherwise it
gathers dust. A lot of dust since I lost the plastic cap for the pressure
relief and the thing is kind of coated in oil...
I have to laugh though. I've heard time and again how unfair and inaccurate
the stereotype of the cheap ham is.....and then there is this thread!
I did buy an inexpensive smoke generator for testing auto EVAP systems
recently. Basically, it is a paint can containing a wick wrapped with
nichrome wire and an LPG regulator to supply 1 or 2 PSI of air. You put
mineral oil in the can. The directions were poor and I filled the can up not
really understanding that the wick at the bottom of the can was supposed to be
above the oil level - it generates the smoke when heated. Before I applied
compressed air, oil was oozing out of the regulator. What a mess! As a
result, I have a surplus of USP grade mineral oil right now.....
Best,
Al
AB2ZY
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Bryan
Swadener via TowerTalk
Sent: Sunday, November 29, 2015 9:03 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Oil For Dummy Load
No, especially when you're pumping a kilowatt into a 90W-rated Globar in only a
gallon of media that has only the tin bucket itself to transfer the heat to
atmosphere. You need _every bit of advantage_ you can get. As it is, those DLs
are rated a kilowatt for only a few seconds. That's why I stopped using my HN31
with an amplifier, and built my compact 1500W (100% D/C) load.
Bryan WA7PRC
From: D. Scott MacKenzie
To: Bryan WA7PRC
Sent: Sunday, November 29, 2015 5:42 PM
Subject: RE: [TowerTalk] Oil For Dummy Load
Mineral oil is a proper substitute - and not "dubious."
-----Original Message-----
From: Bryan WA7PRC
Sent: Sunday, November 29, 2015 8:27 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Oil For Dummy Load
I found one gallon of actual transformer oil for FREE (unless you count having
to drive 2 miles to get it).Why mess around with dubious substitutes when it's
available for FREE?
Bryan WA7PRC
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