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 industrial sector.
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 magnetron-based cooking.
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.
Is the 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 story?
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. What gives?
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 power?
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 140F, etc.
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 so easy.
Click here to return to the main Radarange Central Webpage!