Jeff Weinberg, W8CQ

Your World-Wide Source For Amateur Radio Amplifier Parts & Upgrade Kits

Your World-Wide Source For Amateur Radio Amplifier Parts & Upgrade Kits
12 July 2021: Due to a flood at my home/shop, Harbach Electronics is closed until I get this mess cleaned up and all of the damage repaired. Effective immediately I will be closed for 30-60 days or how ever long it takes to clean up and repair the damage. All pending orders will be canceled and refunded via the method of payment. I am sorry for the closure but I have to get things repaired and cleaned up. I will be back but it will be a little while. If you wish to order Dean Jacobs racing gear, please email me at and send me your phone number and I will contact you and process your order.
You can still view products, but no orders are being taken at this time. Sorry for the inconvenience!

RES-400 5-Pack of HV Safety Resistors


SKU: RES400 Category:


The RES-400 is a direct replacement for the original IRC SPH-style 0.82Ω 2W safety resistors used in the Drake L-4/L-4B/L-7 remote power supply and in the L-75 amplifier.  These resistors are designed to open under conditions of high plate current draw from the power supply (tube arc or power supply short) to protect expensive tubes and power supply components.  They are sold in packs of 5.

Additional information

Weight 0.03 lbs
Dimensions 3.0 × 1.0 × 0.25 in