[heathkit] AR1500 info

[KentRegal@aol.com]

Sounds like you don't have much experience in electronics, so it is good to 
approach a new piece of equipment with caution.  Too bad it didn't come with 
the manual.

The AR1500 AC power cord is two wire non-polarized because it goes straight 
to the primary of the main Transformer, via the front lower right switch and a 
fuse on the back panel.  One of the three secondaries is ground referenced at 
the centertap for the +/- 43 volt supply that feeds power to the Output amp 
circuits.  The dial lamps are 6 volts AC ..... not DC. Since it is a low voltage 
it is reasonably safe level. The transformer isolates the incoming AC from 
the chassis. Only the DC voltages that are derived from it are referenced to 
ground. A very common method of equipment construction ... even today.

There are a couple of websites that have copies of the schematics to 
download. I'm sure someone has that address handy.  The assembly manual is over 230 
pages with many mutiple-page fold out pages. It would be nearly prohibitive to 
try to copy it. However the schematics can be copied,  it is made up of eight 
pages of 8 1/2 x11 , single sided.

The only time I had a HOT chassis was when I had put the bottom panel on 
after some servicing and had caught one of the AC wires in between ! !  That was a 
bit of a surprise! Good thing, all I got was a mild tingle. It could have 
been fatal. The main transformer is in a tight space and the wires are a bit 
stiff.

Common replacement items are the panel lamps, they are #44 type. I have never 
had to replace the stereo indicator lamp, a #1813.  The fuse should be a 3AG 
style, 4 amp slo-blo, for 120 volts and a 2 Amp for 240 volts input..... 
meaning this is useable in most parts of the world ..... just a minor internal 
wiring change .... not as convienient as todays equipment.

You'll probably want to replace the two 500 uF main filter caps and probably 
most of the DC power supply polarized caps. If there is any corrosion near 
their leads that is an indicator of needing replacement.  If this has the two 
original main caps they have a small vent on the top between the screw terminals. 
If there is corrosion there, they are due for replacement. Other than that it 
should work fine. maybe a broken switch function or two, like my main power 
switch failed in the always ON mode so I added an extension cord that has a 
remote switch that I use to turn this 30 year old receiver on with.

Kent Regal