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Description
This is a very clean Heathkit SG-18A low distortion audio generator, capable of supplying both sine and square wave signals from 1 Hz to 100 KHz with distortion less than 0.1 % and with metered amplitude up to 10 volts. This is a factory wired unit, and except for color it is identical to the later models IG-18A & IG-5218.
This is an excellent audio generator, often sought after by Hi-Fi enthusiasts when it was first introduced. An article about this equipment, written by Hi-Fi guru Reginald Williamson (the guy who invented the Williamson ultra-linear amplifier), and titled "The Greening of the IG-18", appeared in the January 1971 Hi-Fi magazine "The Audio Amateur." It outlined several simple modifications that would, in his opinion, make the signal generator even better. Heath later incorporated some of these suggestions into the IG-18A and later production. I noted one of these improvements when calibrating this unit. A copy of the article is included with this auction.
This generator is shown in the second photo putting out nice, clean 5 KHz sine and square waves at a full 10 volts RMS output. (The 'scope, of course, is not included in the auction.) For those of you who are looking carefully, please note that the amplitude of the 'scope traces is un-calibrated and the sine and square waves are not precisely in phase. This is because the SG-18A is first of all an ultra low distortion sine wave oscillator. Its output is fed through a buffer amplifier to the front panel and to a squaring circuit before being presented as an output. The passage through the squaring circuits adds a bit of delay to that signal.
The exterior of the instrument is very nice and the interior is clean and free of corrosion. It has been calibrated, works properly, and would make a great addition to your test bench. Included is a clean reprint of the factory wired SG-18 manual. The Reginald Williamson article will be supplied in printed form as shown. Please observe that a previous owner apparently tried to clean the face of this instrument with an aggressive solvent, and smeared some of the front panel writing (Photo 1).
If you'd like a great audio signal generator, then you'd surely like this one!
Very carefully packed and shipped via FedEx Ground or USPS to the US and Canada. A small 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. 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.
This is an excellent audio generator, often sought after by Hi-Fi enthusiasts when it was first introduced. An article about this equipment, written by Hi-Fi guru Reginald Williamson (the guy who invented the Williamson ultra-linear amplifier), and titled "The Greening of the IG-18", appeared in the January 1971 Hi-Fi magazine "The Audio Amateur." It outlined several simple modifications that would, in his opinion, make the signal generator even better. Heath later incorporated some of these suggestions into the IG-18A and later production. I noted one of these improvements when calibrating this unit. A copy of the article is included with this auction.
This generator is shown in the second photo putting out nice, clean 5 KHz sine and square waves at a full 10 volts RMS output. (The 'scope, of course, is not included in the auction.) For those of you who are looking carefully, please note that the amplitude of the 'scope traces is un-calibrated and the sine and square waves are not precisely in phase. This is because the SG-18A is first of all an ultra low distortion sine wave oscillator. Its output is fed through a buffer amplifier to the front panel and to a squaring circuit before being presented as an output. The passage through the squaring circuits adds a bit of delay to that signal.
The exterior of the instrument is very nice and the interior is clean and free of corrosion. It has been calibrated, works properly, and would make a great addition to your test bench. Included is a clean reprint of the factory wired SG-18 manual. The Reginald Williamson article will be supplied in printed form as shown. Please observe that a previous owner apparently tried to clean the face of this instrument with an aggressive solvent, and smeared some of the front panel writing (Photo 1).
If you'd like a great audio signal generator, then you'd surely like this one!
Very carefully packed and shipped via FedEx Ground or USPS to the US and Canada. A small 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. 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.
Payment
PayPal payments to be made within 3 days of auction end. Contact me before bidding if you must make other payment arrangements.
Shipping
Ships to the continental US and to Canada via FedEx or USPS. There is no handling charge. However, the cost of packaging materials has been added to the shipping calculator. See the item description for details. Buyer is responsible for tariffs, if any. Overseas shipping is not generally available. If the rate calculator does not give shipping rates to your destination, contact me for information before bidding.
Terms of Sale
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.
About Us
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!
Contact Us
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