Knight | Space Spanner

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Morgan Freeman
Actor Morgan Freeman at the dials of a Space Spanner when he was in the Air Force around 1956.
Click here to see a rotated version of the photo.


These headphones belonged to James Kasper and came with the Space Spanner from ebay. Allied sold an antenna and a pair of headphones to augment the radio. I was hoping these would be the ones in the catalog.

Unfortunately, this headset doesn't even appear in the catalog.
These are CANNON-BALL "Empires."
Allied carried
CANNON-BALL "Master" and "Chief" headphones in 1957 and '58, but not "Empire."
These are the Allied brand headphones sold in the 1957 catalog next to the picture of the Space Spanner. They were $2 and rated at 2000 ohms. An upgrade to a CANNON-BALL "Chief" or "Master" would cost 22 or 44 more.


Why do so many Space Spanners have a missing knob on the antenna tune control?
One of the manuals shows the knob missing, but the parts list shows FOUR knobs were included.
On the left is a photo of the antenna tune control before I cleaned the front panel. From the mark on the panel, it is obvious that it once had a knob, and the knob came into contact with the front panel. On the right is the answer to the mystery, one of the greatest mysteries of the 20th Century, second only to whether or not Billy Shepherd replaced Paul McCartney.

The mystery has been solved! See that backed out set screw in the picture on the right? It's the answer.

The instructions in the manual say to remove the set screw. The reason for this is that as you tune the antenna, the shaft on the control moves inward or outward. A knob with a set screw will prevent the control from moving inward when the knob comes into contact with the front panel.

Without the set screw, the knob could come off if the shaft on the control was recessed too far. That is the answer to the mystery. The knobs are missing because THEY FELL OFF.

There is no reason why anyone should open the control so far that the knob would fall off, but it was done. One person told me he closed it so tightly he stripped the threads. Some people boast they built a Space Spanner when they were twelve years old. Maybe so, but some of them didn't understand the function of the antenna tune capacitor when they were twelve.

At any rate, Allied didn't sell a replacement knob! You can buy the knobs today from Davies Molding (the manufacturer of the original Daka-Ware knobs) but it's a lot easier to order from Antique Electronic Supply. They are number 1600 and 1610. Link

Can you actually "GENTLY force" something? "I'm going to GENTLY force your hand into the garbage disposal." "I'm going to GENTLY force you to give me all your money." "I'm going to GENTLY force this knife into your back" It doesn't seem to work in all situations.


The antenna tune capacitor is not perpendicular to the front panel. It's because of the "ears" on either side, which are the electrical connections. One comes from the front and the other comes from the back. I tried bending them, but they just flattened out again as the screws were tightened.

Fortunately, there is no electrical connection with the shaft, so if the shaft comes into contact with the front panel it won't affect the radio. However, we can't have this, the situation is must be resolved at all costs!
A quick fix was to shim it with a washer on one side.
Warning; The ceramic standoffs are fragile and can be ruined by over-tightening the screws.


The big resistor in the filament string (R-11) gets hot. Resistor R-9 is in contact with R-11. The instructions don't describe anything different about soldering in R-9, but the drawing does. It shows R-9 some distance away from R-11.

In ten minutes, R-11 reached a temperature of 192F. Is that a problem? When R-9 was heated by R-11 the value went down by two ohms. It's connected to the cathode of the 50C5 audio output tube. Considering the schematic calls for a 180Ω resistor (10% tolerance) but R-9 actually tests at 209Ω. I don't think it makes any difference. It already exceeds the 10% tolerance by 3 percent anyway.

R-11 was pushed closer to the chassis to put some empty space between it and R-9.


The Space Spanner had a short life of seven years. In 1959, Knight added the Span Master to its catalog of kits. It cost more but had sleek styling and two additional bands. It also sported a "fine regen" control for precision adjustment. This was serious competition.

In 1963 the Knight Star Roamer kit appeared. The Star Roamer was a Superheterodyne radio and had many advantages over the Space Spanner and Span Master.  It also had three times as many parts and a price tag to match. In 1963 the Space Spanner cost $18.95. The Star Roamer cost $39.95. In 2020 dollars that's $160 for the Space Spanner and $338 for the Star Roamer.

In 1964 the Space Spanner disappeared from the Allied catalog. 1968 was the last year for the Span Master. In 1970 the Span Master II was offered, but it wasn't a regen radio. The price was $29.95

Note: These are "entry level" radio kits. You could always spend $500.00 to $1000.00 on a communication receiver if you had the money. See the link to the catalogs at the bottom of the next page.

By the way, I paid about $160 for the Space Spanner, so I got it at the 1963 price! (Adjusted for inflation, of course.) The worth of these radios barely keeps up with inflation, but the headphones I got with the radio have gone up in value about 20-fold.

Unassembled Space Spanner
Here's an unassembled Space Spanner. Photo from an ebay auction (I didn't bid on it).
If you owned this, would you assemble it?