HA-14 "Kompact Kilowatt"
The Heathkit HA-14 ("Kompact Kilowatt or KW Kompact") system was released in 1965 to a surprised and delighted market. Like the game changing HW ("Hot Water") 200 watt SSB monobanders released earlier, it was a model of simple elegance both circuit wise and in appearance. Carefully targeted to a narrow but enthusiastic audience, it did not try to be all things to all hams. It was simply a small, affordable, one Kilowatt SSB-only linear amplifier for the car and home.
Like the matching HW-12/22/32 monobanders it came with optional mobile and base power supplies. The size, color and shape even matched the monobanders for easy stacking. Being for SSB operation only, the cooling and power supplies were designed accordingly. For maximum air flow through the tubes, operation would be in a nominally horizontal position. Neither the HA-14 nor the HW monobanders were designed for AM or CW or other high duty cycle modes.
I remember those exciting days and the surprises that came with each new Heathkit catalog. In time I came to own all of these, and for many years ran most of them both fixed and mobile ('68 VW Beetle and '69 Chrysler T&C). They fulfilled their promise and were great fun both to build and operate!
Over the years the HA-14 has developed a reputation as a powerful and reliable mobile SSB Kilowatt when operated as intended. This includes tuning the antenna properly, first. Since it has fixed loading with a 50 ohm output it is meant to feed an antenna correctly tuned to the 50-75 ohm impedance range. A built-in SWR bridge and meter make for easy monitoring.
The HA-14 amplifier uses two 572B power tubes in parallel in a traditional grounded grid configuration. The matching power supplies are solid state.
Since this amplifier serves as a small and affordable home KW it works very well in fixed station service. Perhaps more of them are used fixed than mobile. I ran one fixed every day for years while feeding dipoles and a cubical quad antenna, driven by a variety of Heathkit HW(-A-version) monobanders and SB- transceivers. They worked the world!
In fixed service, where ragchewing or contesting may be more intense, it is important to supplement the tube cooling, especially if the amplifier is in an enclosed space. Adequate cooling is easily achieved by laying a large 'muffin fan' on top of the case above the tubes. To minimize air leaks between the fan housing and the amplifier case build a simple 'gasket' between them using weather stripping. To keep the fan noise low add a resistor in the fan lead to slow it down.
It doesn't take a lot of extra airflow to keep the HA-14 noticeably cooler. Some users mount a small fan or two on the backside. Since the 572B's are 'instant on' tubes, further cooling is achieved by switching it off except as needed.
Kilowatt Kompact's have been a bit difficult to find for many years, especially with the HP-14 mobile power supply. But in the current economic environment they appear from time to time. Good luck, and ENJOY!
Observe the scorch marks on the top right of the case, directly above the amplifier tubes. This HA-14 has been "run hot and put away wet". Chances are these finals were overworked and undercooled and may be soft. Proper cooling would probably have avoided this damage.
More information:
Click Here for HA-14 Linear Amplifier
Click Here for HP-14 DC Power Supply
Click Here for HP-24 AC Power Supply
Click Here for the Cables/Connectors
Bad mods, cautions, restoration, misc...
Modifying The Heath HA-14 For 6 Meters - by W7MY
NOTE
If you have a good KW Kompact tale or photo or article or mod or link or suggestions which could help other KwK owners please send them along to W6OVP@arrl.net. TNX.
Send your comments, photos, schematics, hints, articles, stories and links to:
Dave W6OVP@arrl.net Vancouver, WA
