When did the first
home models debut?
The first home version Radarange was released in 1967. The earliest version
has matte-chrome finishing on the upper and lower recesses of the door
(the flat behind the door handle), but the rest of the styling cues are
in place. For 1968 the RR-2 debuted which featured a third button to control
the interior light.
How much did the first RR cost?
Web sources state retail price was $495 in 1967. From receipts I’ve
found in newer models, the price did not drop appreciably until the 1980’s.
My parent's RR-9T was $485 in Feb '79. One look inside one of these machines
and it’s easy to tell you get what you pay for.
Were there commercial Radaranges?
Yes, in fact Radarange-badged microwave ovens predate the home version
by 20 years. However, due to cost, size and other restrictions (such as
water cooling and 220V service), they were limited to the commercial and
I saw a Frigidaire
microwave that looks like an RR, what's the scoop?
These are actually Radaranges in disguise. Internally, they are
equivalent to the RR-9 with the old-style magnetron, heavy duty power
supply and overbuilt chassis. An RCM-9 is in the collection featuring
woodgrain and digital controls. Oddly, Current, and not Wattage, is a
parameter on the dataplate. Manufactured date is July of 1977.
Yeah, but what about Tappan?
In 1955 Tappan, using Raytheon licensed technology, offered a built-in
wall-mount microwave oven to match their conventional oven line. Due to
cost and complexity, they were not popular.
Where does Raytheon come in?
The microwave technology in the Radarange is actually a Raytheon creation.
Raytheon was founded as the American Appliance Company in the 1920s by
three tech minded individuals (one of whom was Vannevar Bush, of all people!).
During WW2, the company actually supplied 80% of the magnetron tubes used
for allied-forces radar. Out of radar development came the discovery of
But what’s the Amana tie?
With the development of an air cooled, affordable magnetron, Raytheon
knew they could develop microwave cooking for home use, but they needed
a manufacturing arm. In 1965 they bought Amana Refrigeration and developed
what would become the RR-1. Raytheon spun-off Amana in 1997.
candy bar story real?
The story goes that Percy Spencer was standing in front of an active Radar
transmitter and noticed the candy bar in his shirt pocket was starting
to melt. He seized on this idea and an industry was soon born. I’ve
also read variations of this tale, but we’ll probably never know
the real story.
I've seen Radaranges that appear to be built into the wall, what's the
Since these machines draw air in through the bottom and are not
rated for direct surface contact, they cannot be "built-in"
in the standard sense of a wall oven. However, Amana offered a kit that
consists of a galvanized sheetmetal case that slides into the wall opening.
Any standard RR then slides into this case. Louvered trim then fills the
void around the front of the machine, much like a picture frame.
Can a Radarange wear out?
Yes. The magnetron can weaken with use, or be damaged by running under
no-load conditions. Considering the age of these machines, it’s
pretty likely performance is no longer 100%. The good news is that replacement
magnetrons are available, providing new-machine performance.
What can I do to prolong the life of my RR?
By far the biggest thing you can do is to keep the machine clean, both
inside and out. Never operate your RR without a load (even a cup of water
is sufficient) and avoid heavy use of microwave popcorn, which has little
moisture content and can even crack your tray due to localized heating
(tip: place the popcorn bag on an old Correlle dinner plate – they’re
made of tempered Vitrelle).
Can’t microwaves escape through the door glass?
Interestingly, the glass and plastic liners in the door have no appreciable
effect on microwave containment. In fact, the RR-1 and RR-2 have only
a metal screen and no glass at all! It’s the hole size of the pattern
in the metal screen that prevents ‘escape’. Radaranges operate
at 2450MHz; this equates to a wavelength of approximately 12cm which is
clearly larger than the screen holes.
What’s this headphone jack?
See “How do I use the temp probe?”
What does “Touchmatic” mean?
Touchmatic is the trade name for the control panel interface offered on
the digital RR models. The 9T and 10 actually say ‘Touchmatic’
and ‘Touchmatic II’ on the panel glass, though technically the RR-6 would be the first in the Touchmatic series. Stray capacitance
from the human body is coupled through the glass (which acts like the
dielectric of a capacitor) to activate the desired function wherever you
place your finger tip. This also makes cleanup easy since you can wipe
down the glass.
What does “Cookmatic” mean?
Cookmatic is the trade name for the ability to adjust the cooking power
level. Magnetrons only function at full power, so it wasn’t until
the RR-4D that Defrost was featured with a 50/50 duty cycle. With “Cookmatic”,
the duty cycle can be adjusted from 10%-100% linearly. On analog machines,
this is done with a lever or knob depending on model and was referred to as 'Cookmatic Powershift'. On digital machines,
levels 1-9 can be selected through the “Cookmatic” button.
My machine was working fine, but now it’s completely dead.
This is by design. A door interlock system consisting of primary and secondary
switches is designed to keep the RR from operating unless the door is
securely closed. With time, parts can wear and these switches can go out
of adjustment, or, as I’ve seen happen, a door spring breaks and
one of the door arms no longer closes the appropriate interlock switch.
I’ve also seen them fail on their own. When this happens, the primary
internal fuse is designed to blow. Since gaining access to the fuse is
fairly complicated, this helps ensure that repair and adjustment is done
by a qualified technician.
Were Amana RR’s ever sold outside the US?
Yes they were. It’s rare, but I have photos of the 220V, 50Hz equivalent
of the RR-2, RR-6, 10 and other Touchmatic chrome door models. Often with
‘international’ keypad markings. 50Hz machines can be used
in the US, providing the voltage is correct, however, 60Hz machines cannot
be used overseas. Many Canadian-bound machines have a C in the model prefix.
The nameplate on the back says 1500 Watts, is this the cooking
Not exactly. This is total power usage including internal light, timer
and exhaust fan. Magnetrons are terribly inefficient, typically on the
order of 50-60%, but obviously much more efficient in terms of energy
used per given period when compared to heating up a (more electrically
efficient) conventional oven. Rated cooking power is 700 Watts on the early models, and 750 Watts on later models.
How do I change the lightbulb?
The oven interior (known as the cavity) is lit from above. To change the
bulb, you’ll find a small door on the top rear exterior of the RR
secured with 1 or 2 screws (depending on model). Bulbs are readily available
at most hardware stores and are size bayonet type 25T8DC (25 watt).
How do I use the temp probe?
If your RR has a jack provided in the oven cavity, you can make use of
the temp probe option. In fact, there are two probes- a cooking probe
and a candy-making probe for a different temp level; don’t confuse
the two or your results will be way off.
On a mechanical machine, operation is simple. Plug the probe in, insert
the probe in the food to be cooked, and set the desired ‘Holding’
temperature. You then set the timer to zero to start cooking and the food
will heat to the desired temp and then enter a ‘Holding’ state
where cooking power will cycle to maintain temp. The Cookmatic Level/Defrost
features can be used as well should you want a controlled ramp up.
On digital machines, the concept is the same, but there’s greater
functionality, including the ability to use the temp probe as a monitor
while operating the machine normally. (insert temp probe, touch 'Temp
Control' and the number displayed is the 10's digit of the temp. For example,
if "3" is displayed, the food is 130F. If 4 is displayed, it's
How do I set the time on an RR-700
The RR-700’s have black fronts and two silver knobs over black glass.
To set the time, you hold in the Start button until the display reads
12:00. Use the timer knob to set the time, then press Start again.
What is Radarware?
Radarware is the name of Amana’s line of Radarange cooking accessories.
This includes their popcorn maker, coffee maker, crispers, browning skillets
and other cookware. Many pieces were made by Corning and have microwave
absorptive material embedded within that converts the microwave energy
into conductive thermal energy (heat). I’ve tried making burgers
and even pizza with these accessories and they do a surprisingly good
job. (See the Collection area for examples)
Why are the old Radaranges so heavy?
First, there’s a lot of steel, iron and copper in these machines.
Not only in the cabinet and controls, but especially in the power supply.
Magnetron tubes require a magnetic field to operate and this was achieved
on the later machines (RR-4D and newer) by way of permanent magnets. But
the early machines use an electromagnet arrangement, which means the power
transformer (already an impressive sight) is even larger and heavier.
Plus the weight of the E-magnet itself. In the late 1970’s, a reduction
in weight was achieved by switching to a smaller, more efficient magnetron
tube (models newer than RR-6). Eventually the bean-counters got involved
and internal sheetmetal got thinner, power transformers got skimpier,
and the heavy chrome doors went away.
My RR says model XYZ on the back, but it looks nothing like the
one on your page.
This is usually the result of a compatible replacement control panel being
installed sometime after the original failed. The dead giveaway is that
the display is now greenish/blue rather than red LEDs, and the panel surface
is not a true touchplate, but rather dome switches behind a plastic lookalike
panel. Some of the last chrome door models made use these panels “from
new” but have their own unique model number, such as the RR-8T.
I have model XYZ, do you want to buy it?
The biggest problem with buying these RR’s is dealing with the shipping
(or should I say, freight!). If you’re not too far from Iowa, and
you’re looking for a home for an RR, it never hurts to contact me.
For the most part though, I’m pretty full-up.
What models are you looking for?
I’m always interested in the early stuff, especially an RR-1. If
you’ve got one, let me know.
What’s my machine worth?
When the economy was bustling, there were folks on that popular auction
site willing to pay several hundred dollars for a clean RR, plus the $100
shipping charge. I haven’t seen that happen in some time. As it
stands today, they’re worth whatever someone is willing to give,
especially considering shipping/damage control. A $20 bill will still
pick up these beasts on craigslist and garage sales if you’re patient.
Is any one model better than the others?
That all depends on what you’re going for….
For a real retro-look, you want the RR-4D. It gives you bullet-proof reliability
plus defrost, but it uses the old style magnetron so cooking power is
a little weaker than the newer models.
If you like digital, look for a late 70’s RR-9T or 10 model (marked
Touchmatic/Touchmatic II on the panel). Both have the newer magnetron
and lots of great features. Reliability is pretty good, but these panels
might need a re-cap as the electronic components are now 30+ years old.
With a re-cap, they’re stellar.
And if you want good performance and something that’ll survive an
EMP, you can’t go wrong with an 8A, 5B or 7x model. Sometimes marked
‘Cookmatic’. The timers are completely mechanical and the
magnetrons are the improved type.
Why can’t I put metal in the microwave?
Yes, the cavity is metal and so is the door screen, but those surfaces
are large enough to reflect the radio energy from the magnetron without
issue. The problem with most metal objects is that they act like an antenna
in a high-energy field, especially thin metals or those with sharp edges.
This energy will localize with sufficient charge to break down the dielectric
strength of air and arc over. This is not good. Like two high voltage
wires shorting to each other without a series load, the magnetron sees
this arc-over as a short and effectively ends up destroyed.
My control panel has been acting erratic, what can I do?
The filtering capacitors in the control panel power supply circuit are
beginning to fail. If you have a 9T or 10, then the good news is the panel
is easily removable and can be sent in for repair (see the Repair Service
section). 6/6W can be repaired as well, but removing the panel isn’t
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