The Boatanchor Cooler (BAC) System for vintage Collins tube type Receivers, Transmitters, Power Supplies, and Amplifiers; was Designed and Engineered by K4ZRD, as a result of High Temperature readings found within various older pieces of our Collins S-Line radio equipment being operated over an extended period of time. Constant high temperatures and heat resulting from Tube and Transformer dissipations were well known to degrade aging capacitors, resistors, coil forms, diodes, ceramic tube sockets, terminal boards, insulation on wiring, cause arcing from tube sockets to chassis, and other types of component problems. Heat may also effects the frequency stability and cause off frequency conditions in our valued equipment such as in the Collins S-Line PTO circuit.

Readings made on my Collins KWM-2A without a cooling fan found that starting in an Air Conditioned Room with a Temperature of 77.0 degrees Fahrenheit over an hour and a half period of time the "under the lid" temperature sharply rose to 116.0 degrees. After two hours, that temperature had again risen to 126 degrees - all within the cabinet. The same type readings within my 32S-3A transmitter were 127 degrees, within the 75S-3C receiver 125 degrees, within the 516F-2 Power Supply 118 degrees, and within the 30L-1 Amplifier to 127 degrees. All tests were conducted using a precision Fluke Thermocouple device. Replacement parts for failed and damaged components are often very hard to locate , or we pay a premium price for their replacement when these types of problems can be minimumized with preventative measures for the damaging heat.

From discussions with numerous other Collins Collectors and Operators I found that some Collins Owners are actually tapping into a filament voltage point under the chassis, or many times using a splitter-adapter to obtain the 6.3 volts off the rear panel RCA jack on the 32S-Series transmitters. Some were using cheap Wall-Warts to produce voltages to drive a “single” cooling fan. All of these methods are limited in the number of fans which can be utilized. Many of these methods add onto, or may even exceed the actual voltage limits of our Power Supplies. The method of tapping off a filament string or using a splitter on the 6.3vdc jack, has often resulted in shorting out a component, blowing the internal fuse under the unit chassis, or destroying a component in our power supplies from overloading.

Much discussion and debate has been held and aired on the Internet regarding wheather to place fans on top of the cabinet lids verses utilizing a bracket under the lid, as well as running 6.3vdc, 12vdc, 24vdc, 48vdc, or even highly dangerous and lethal 120 volts AC into the insides of our units “just to run fans”. Hot Air from the units must be "pulled out" - not blown back in or just simply moved around inside .

Dangerous high temperature heat can results in the roasting, blistering, or cracking of any vintage component - which will eventually lead to the rupturing and failure of these well aged components. The effects of high damaging temperatures must be minimumized from their sources - which are tubes and transformers. Not even by blowing air from under the chassis to cool those particular components will eliminate the source of the heating problem. Aging components manufactured in the 1950s, 1960s, and 1970s are now very susceptible to prolonged heating problems.

In an effort to find a power source which was independent from our Collins equipment, and one which could economically and safely handle multiple fans, to cool numerous units at the same time, I designed - what I call the Boatanchor Cooler System (BAC) for Vintage radios. The Cooler Power unit was designed from a Computer Power Supply, to operate on either a 120 or 240 volts AC - source, and is switchable from the rear panel. There is a RF and Spike Suppressor circuit already designed across the two AC lines consisting of a capacitor and resistor to safeguard against AC voltage Spikes. Both AC lines are broken with a DPDT Toggle switch for circuit and operator safety. A third AC wire is grounded to the chassis. A "StarBright White-Red - 5,000mcd LED" pilot light is on the front panel operating at 1.9 volts which indicates power is applied to the unit. An internal cooling fan operates to provide for continuous air circulation within the unit. Output from the unit is fed thru two high quality RCA Jacks on the back panel. The power unit is a heavy duty solid state Full wave bridge rectifier switching power supply which will provide regulated voltages at 9.0 amps sufficient to drive multiple cooling fans off the two RCA jacks. Tests utilizing a number of commercial quality Splitters off the two rear panel RCA jacks has successfully operated sixteen ( 16 ) 80mm fans drawing 140 milliamps each, over an eighty ( 80 ) hour period of time off this supply. I also wired a regular Red LED into each fan to show it was operating. An oscilloscope reflected that the output voltages from the supply are extremely clean, and have not caused interference on my own radio equipment. The AC line is also fused on the circuit board. Heavy duty heat sinks and the internal cooling fan maintains the unit running in a continuous cool condition for weeks and months at a time. Over the past five (5) years I have run the same BAC for 18 hours a day-every day on top of our Sterio - Home Theater System with no failures of any kind. Two 10 ohm 5 watt resistors are tied together in parallel for better regulated long-term voltage output from the RCA jacks.

By utilizing a single 80mm fan placed on top of a Collins KWM-2A I have measured a constant temperature between 85 to 89 degrees Fahrenheit over a twenty hour operation of the unit. Tests with other S-Line units has shown similar readings. This is a very small increase in temperature verses the previous high temperatures I found without the fan. The 80mm fans are quiet and remove a constant volume of hot air, dust, and in our case "dog hair", from receivers, transmitters, power supplies, and the 30L-1 Amplifier. All the components including the Computer Power Supply, RCA Jacks, Resistors, Fans, LEDs, AC Power Cord, DPDT Switch, Rubber Feet, Fan Grills, and the Lexan Front Plate are available on the Internet. The whole unit with two fan kits should run around $35.00. If you wish to place either a Reproduction Round or Winged Emblem on the front panel, they are available from the Collins Radio Association (CRA).