Barry's 8 Track and |
Call 928-533-9666 |
- 100's of NEW motors in stock - - No extra charge for MP3 input - |
- 8 Track Repair Specialist - - Certified Technician - |
BBB ACCREDITED DEALER for Aurora Design FM Conversion Products |
How We Do the FM Conversion BETTER ! |
We Add More Heatsinking For Better Reliability! |
Question: What is the most common cause of failure in electronics? Answer: HEAT |
There are many shops who perform FM conversions using the Aurora Design FMR-1 module. Almost all of them simply mount the FMR-1 directly to the radio chassis, hoping that the thin metal housing will dissipate enough heat to keep the module safe from overheating - and to be completely honest, this is probably all right. HOWEVER - Your converted, high-power radio won't be operating on the bench, opened up in a room at a comfortable ambient temperature to allow the heat to escape. It will be inside an effectively sealed cabinet, behind the dash and enduring the heat of the hot summer months at times. Your air conditioning system is designed to cool the space occupied by driver and passenger, and won't offer any cooling behind the dash until the entire car has been at a comfortable temperature for quite some time. Meanwhile, you're enjoying music at a high volume while your radio begs for mercy. Keep in mind that the FMR-1 module is capable of 180 watts when pushing 4 speakers. This is more power than most professional stage guitar amplifiers, jammed into the tiny cabinet of a car radio - with no fan, no airflow, and simply not enough cabinet surface area to dissipate much appreciable heat. For this reason, HEATSINKING is necessary - and is widely used in virtually every high-power amplifier on the market, regardless of type. Now, let's read some excerpts from the FMR-1 installation manual: |
"Since many radio chassis are thin sheet metal which does not provide much in the way of heat dissipative properties, it is recommended to place a piece of 3/16 (4.75 mm) or 1/4" (6 mm) thick aluminum as large as can possibly be fit in the radio..... Then in bold, red print: "Note: It cannot be stressed enough that adequate heat sinking for the FMR-1 module must be provided. Failure to do so can result in thermal shutdown or long term reliability issues. Always add as much heat sinking as possible and use a good quality heat sink grease for best operation!" |
I will add my own precaution: "Long term reliability issues" mentioned above means that your expensive FMR-1 module might appear to do just fine, but then fail AFTER the warranty expires due to a heat-stressed output chip! |
Now I'll show you what we do that most other shops don't: |
From a piece of brand new flat aluminum stock, we measure and cut a piece to fit your radio, bending it on our bending brake into a "U" shape for maximum surface area as space permits. |
Rather than making the heat sink small enough to clear everything, we make it as large as possible for maximum surface area and heat dissipation - then notch and shape it as needed to clear the 8 track tape (below) and allow for safe wire routing and cabinet screws (above). |
More views, showing the heat sink, NEW MOTOR and hand-built speed control board ('70 Barracuda Radio/8 Track) |
Notch on underside to clear the track change/eject plunger switch |
Two identical units, before and after FMR-1 conversion and motor replacement |
Comments from the designer of the Aurora FMR-1: "Very nice. Not only does that add extra surface area, but it spreads it out over the steel chassis." "Steel actually has pretty mediocre heat properties, so spreading it out really helps." "While the radio may not absolutely need it, the more heatsinking the better!" |