Richard Knoppow wrote:
----- Original Message ----- From: "Garey Barrell" <[email protected]>
To: "Drakelist" <[email protected]>
Sent: Thursday, March 11, 2010 1:31 PM
Subject: Re: [Drakelist] receiver xformer
Richard Knoppow wrote:
----- Original Message ----- From: "Garey Barrell"
<[email protected]>
To: "Drakelist" <[email protected]>
Sent: Thursday, March 11, 2010 11:12 AM
Subject: Re: [Drakelist] receiver xformer
Geoff -
True! Fortunately, our Drake gear has dual primary transformers,
so just a matter of moving a few wires or even just moving a switch!
73, Garey - K4OAH
Glen Allen, VA
Gary, the problem is not with the voltage but the frequency. At
50hz the inductance drops and a larger core is needed, otherwise the
transformer looses efficiency and will run very hot.
Another reason transformers may run hot is from very distorted
waveforms on the power line. At least in the US this is more often
the case than not. Looking at the power line waveform with a good
scope may discover all sorts of things.
I've been running my R4 B all day lately and will check the
transformer later.
OK... My R-4B has been on all morning (about seven hours). It sits
under an open-backed shelf that is 2.5" above it. The transformer
measures 51.7 degrees Celsius, well within "normal" temperature for
electronic equipment. This receiver DOES have a new "hayseedhamfest"
electrolytic in it, which would probably be the most likely "fault"
to cause increased transformer temperature.
73, Garey - K4OAH
Glen Allen, VA
Mine is quite a bit hotter, around 135F (57C) measured with an
electronic thermometer. The sensor of the thermometer was held against
the top of the core until the reading stabilized. Ambient here is
about 80F (27C) right now.
I have fresh filter caps in it although I have not yet installed
the one from Hayseed.
I rechecked mine last night. It was reading 54.3 on a "non-contact"
type ( used earlier) and 51.7 with my Fluke contact type. There was
minimal variation between the side or the top of the lamination stack.
The receiver had been on for over 10 hours at that point, so probably
has reached equilibrium. My line voltage is very stable at 122 VAC just
about any time I measure it.
73, Garey - K4OAH
Glen Allen, VA
_______________________________________________
Drakelist mailing list
[email protected]
http://mailman.zerobeat.net/mailman/listinfo/drakelist
