Heathkit W7-A Cable Harness and Wire Dressing
- I am working on restoring two Heathkit W-7 mono amps.
- One is a W-7A and the other is a W-7M, but the real difference is that one has the wiring harnesses intact and the other one I am going through the process of rebuilding.
- I am guessing that the cable harnesses were originally built in the mid/late 50s for ease of installation, speed of installation, perhaps even keeping the technology equivalent to the market level planned for the product, to not encroach other, higher ranked Heathkit products, but things might have improved since then. Other changes I will upgrade: Diode Voltage multipliers, Selenium rectifier replacement, Surgistors replacement, Capacitors are all improving and upgrading, why not other wire routing improvements?
- One of the initial concerns that jumps out to me is that Heater wires for the EL34 and the 6AN8 (or 6AN8A). They are grouped tightly right there with all the other wires. This occurs for both the heater wires for the 6AN8 (cable P)and the EL34 (cable R), the power switch, among other things.
- General Picture of existing system with orderly cable harness.
- Cable P & R, with markups where some of the major wires go.
Possible solutions I am thinking of? What are your thoughts; are any of these needed?
- Twisted pairs of Heater wires and power switch line.
- Separate the twisted lines to a parallel cable harness at least a CM away from existing one.
- Anything else I should be looking at to twist cable and separate out?
Later edit: I am also exploring switching the 6AN8 heater circuit to DC so that also opens up changing the path from the octal PreAmp socket.
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