Heathkit SM-2410 (IM-2410) 225 MHz Frequency Counter - HAM

Here's a very nice Heath SM-2410 frequency counter that is in excellent working condition.  The SM-2420 is the factory wired version of the IM-2410 counter - perhaps important if you want to know it was done correctly.  Most counters have only a low impedance 50-ohm input above 50 MHz.  The high impedance input of the IM-2410 allows you to make measurements at the higher frequencies without loading your circuit.  It has a full eight digit readout for maximum accuracy and resolution.

The IM-2410 is an extremely easy to use counter, even for a beginner.  Just connect to your circuit, select the frequency range you want and the gate time.  The longer gate will give more resolution at the expense of longer update time.  This instrument has been recently calibrated, and is quite accurate and stable.  It is shown in the first photo measuring the 225 MHz output of my HP 8657B signal generator. An extra digit of resolution could have been had by selecting the longer 1 sec. gate.  The second photo shows it measuring the 10 MHz output of a primary frequency standard that is kept phase-locked to the cesium standards of the DOD GPS system.

This instrument appears nearly new, is working properly, and meets or exceeds its published specifications.  One repair has been made.  The original oscillator calibration capacitor failed and the exact replacements is not available.  It has been replaced with a high quality NPO (temperature compensated) trimmer capacitor which is held in proper position on the circuit board for external adjustment by a small dab of silicone adhesive.  It can be seen in the chassis photo at the lower right corner.

This instrument ships with the complete IM-2410 manual set on CD in PDF format. The set includs the assembly and operation manual, pictorial diagram booklet, and the separate schematic diagram.  The cable used to connect my signal generator is not included.

A good frequency counter is a real necessity if you work with any electronic equipment, but especially if you don't have a fancy synthesized signal generator with a digital display.  With this counter, you can have the accuracy of the fancy generators at a fraction of the price.


Your instrument will be very carefully packed and shipped via Priority Mail to the US and Canada.  A small fee has been added to the shipping calculator to cover the cost of a new packing materials because I know you want your purchase to arrive safely.  I ship at my cost.  There are no extra charges.  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.