Heathkit C-3 Capacitor Checker - Accurate! - HAM

Here's another nice, clean Heathkit model C-3 capacitance and resistance bridge from my collection.  It's shown in the second and third photos measuring the value of a (nominal) 0.021 µF polystyrene capacitor from my "junk box."  My eyeball reads it as a smidgen over that.  My Fluke digital meter confirms the value as 0.02113 µF.  The Heath C-3 leakage circuit tests capacitors for leakage at their rated voltage, up to 450 VDC.  This is great for finding those capacitors that measure OK on a modern capacitor meter, but just don't work right in tube-type circuits with their higher voltages.  It also measures the power factor of electrolytic capacitors.  This test serves the same purpose as a modern ESR meter.  The Heath C-3 is also a resistance bridge, and is generally more accurate for measuring resistance than the logarithmic scale of a multimeter or VTVM.  I like the C-3.  It uses the same bridge circuit as the later Heath models, and the scales are much easier to read.

All the components in the measuring circuits of this instrument have been checked for accuracy, and both the large 2µF paper capacitor, known for changing value, and the 0.02 µF paper capacitor have been replaced with modern, more stable 1% tolerance ones.  The two electrolytic capacitors in the power supply have also been replaced.  As this instrument was built when the line voltage in the USA was a nominal 110 Volts, per a Heath service bulletin, a voltage dropping resistor has been added (photo 6, center) to compensate for today's higher line voltages.  This ensures that the internal components are not over stressed, and correct voltages are applied to the capacitors you test.  It will be shown on your copy of the schematic diagram.  This instrument is now working properly on all ranges and is quite accurate for its intended purpose as a shop instrument.
 
But measurement accuracy isn't the real reason for having one of these unique instruments.  Read on:

My personal experience is that the Heathkit C-3 is uncanny in finding bad capacitors that other testers miss.  The poor ones just won't open the eye, even when they measure fine with my other meters; or they will show leakage at the higher test voltages that the other meters just don't have.  A tester like this is a real necessity if you work with older radios, TVs or HAM transmitters.

This C-3 ships with a nice, clean reprint of the operation and maintenance sections of the manual, including the schematic diagram.  Only the detailed construction steps have been omitted.  Also included is a new set of suitable test leads.


If you like to work with vintage electronics, this tester will find those bad caps that have been giving you fits!


Very carefully packed and shipped via FedEx Ground or USPS to the US and Canada.  A modest fee has been added to the shipping calculator to cover the cost of a new box and packing materials because I know you want your purchase to arrive safely.  I ship at my cost.  There are no extra charges.  Parcel Select shipping is not available for this item.  BE SURE TO CHECK THE SHIPPING CALCULATOR.  The "Economy" shipping may not be the least expensive to YOUR location.  Good luck with your bidding!

INTERNATIONAL BUYERS: Import duties, taxes and charges are not included in the item price or shipping charges.  These charges are the buyer's responsibility.  Please check with your country's customs office to determine what these additional costs will be prior to bidding.

Detachable power cords, cables and other accessories are not included unless stated. Payments made with PayPal will be shipped to PayPal registered addresses only. Auctions will not be ended early. All eBay rules apply.

My name is John.  I'm not a professional eBay seller, just a retired electronics engineer selling off my collection of electronic equipment acquired over the last half century.  Some of the kit items I built myself back in the mid '50s.  Newer items I acquired as I needed them for my work and hobbies.  A few older items I bought on eBay just for the joy of fixing them up and seeing the vacuum tubes glow again.  Most all the items I'm selling are in good working condition.  The few that aren't will be plainly stated as such.  All items will be accurately described to the best of my ability.  These are not collector items, just good working tools that have lots of useful life left in them.  I warrant that you will receive them as shown and described in the auction.  They are otherwise sold as-is.  I look forward to your business.  Good luck with your bidding!

Preferred contact is through eBay to prevent fraud and loss of messages in the "junk mail" bin.