 |
Lance Borden
"Armstrong one tube Regenerative Receiver"
|
 |
|
|
|
This is an assembled regenerative AM broadcast band
receiver kit, developed and sold by |
Lance
Borden. |
|
It uses a 3S4 vacuum
tube and requires a long wire antenna and ground
connection to operate. |
|
|
|
|
|
|
|
This radio was featured on the cover of
Electronics Handbook in 1996. Download it
here. |
|
|
|
|
Matt Knoebel assembling the radio in
August of 2012. |
| |
|
Parts are mounted, now about
to wire up the set. |
Construction took about 4 hours,
including winding the coil. |
|
| |
|
|
|
An inexpensive 45 volt battery. These are
from a "dollar store." At the time this was built, 9V
batteries were two for a dollar. There is no reason to use
alkaline batteries as the current draw on the battery pack
is very low. |
|
| |
|
|
The batteries are
connected like this.
Cover the top with tape to avoid a short circuit, and make sure the
two exposed wire ends don't touch each other. |
| |
|
| |
|
|
|
This was Matt's first radio. He got no
help, other than some assistance
interpreting the
wiring diagram. Yours truly supplied the 45 volt
battery and a pair of high
impedance headphones. |
|
|
| |
|
|
|
The radio worked the first time
it was turned on. As a matter of fact, I would rate this
little set as EXCELLENT! Local stations are easy to
tune and come in loudly. (Our local station, KYW 1060 is TOO
loud.) The regeneration control is smooth and noise free,
though it can break into oscillation suddenly at higher
frequencies.
Listening at night, if you
disconnect the ground wire you can pick up many distant
stations and even shortwave. I was able to copy an amateur
radio operator using Single Side Band by carefully adjusting
the regeneration control. |
|
|
|
|
| Here's a video of the
set in operation. |
|
| |
The radio under de-construction. The coil
has been removed!
In spite of the set
working so well, in the above photo the coil has been
removed and is about to be rewound.
Why? See the next page! |
|
|
|
|
| |
