The Heathkit IG-102 RF Signal Generator

in this video I'll give an overview and demonstration equipment the Heathkit IG 102 radio frequency signal generator signal generators are electronic devices that generate repeating or non repeating electronic signals and are used in designing testing troubleshooting and repairing electronic devices radio frequency or RF signal generators are capable of producing frequencies in the range used for radio receivers RF signal generators are often used for servicing and aligning radio receivers Heathkit was a manufacturer of electronics in kit form their product line included amateur radio test equipment and various consumer products by building a piece of electronics you could save money and gain the satisfaction of having assembled it yourself the IG 102 is one of youth gets more popular pieces of test equipment it was offered from 1963 to 1977 the 1971 US Heathkit catalog listed at a price of 31 95 while in 1976 it was 44 95 the IG 1 & 2 s was the Berkeley Physics Laboratory version which was identical except for an additional set of jacks for a high level direct output needed for experiments in the laboratory it should be noted that the laboratory version is not suitable for radio and TV servicing as high level RF radiates from the additional jacks one could easily remove or disconnect the extra jacks in the laboratory version to turn it into a standard IG 102 both the IG 102 and IgE 102 s were sold as kits the igw 19 was a factory assembled version of the IG 102 selling for about $10 more than the IG 102 in 1971 as part of their educational products line Heathkit sold the EF 3 course called how to understand and use your signal generator which is intended for use with the IG 102 and included a test chassis model EF 3 2 was a bundle that included both the EF 3 course and the IG 102 generator marketed as the best value in general-purpose RF Raiders BarNone it was said to be the choice of thousands of educational institutions served service shops and laboratories the unit is a pretty standard RF signal generator that can produce amplitude modulated or unmodulated RF signals in six overlapping bands suitable for am/fm TV long wave and shortwave receivers the band's cover the following frequencies band a 100 to 300 20 kilohertz band B 310 to 1100 kilohertz band C one two three megahertz band e 3.1 to 11 megahertz band e 10 to 32 megahertz and band F 32 to 110 megahertz the output voltage was rated at 0.1 volts or higher with an output impedance of 50 ohms the commonly used if' frequencies of 455 kilohertz and ten point seven megahertz are marked on the dial scale an additional scale inside of band F is calibrated for the harmonics of band F from 100 to 200 20 megahertz the unit and the manual list frequencies in cycles per second kilocycles and megacycles as was standard at the time the RF output level is controlled by fine and coarse attenuators but is not calibrated the modulation frequency is fixed at around 400 Hertz and about a 30% modulation level the unit can accept an external modulation input you can also directly output the 400 Hertz audio signal tuning uses a vernier Drive on the dial it used the same size and style of case as some other Heathkit instruments of the period like the I T 11 capacitor checker it came with microphone type input output connectors which are often replaced with more modern and widely available BNC connectors the manual has about three pages covering applications for the generator such as AM radio alignment and signal injection for testing of TV and hi-fi amplifiers let's take a look inside the unit it uses two tubes each of which is a dual tube the 1287 for the RFI so later and a six a and eight amplifier and modulator the power supply uses a silicon diode the coils and band switch were factory assembled and aligned basic alignment could be done without instruments using an AM radio and station of known frequency if you had an accurate shortwave radio receiver that could be tuned to a frequency standard station like WWV you could adjust the coils for additional accuracy band F can be adjusted using an FM radio tuned to a station of known frequency let's see a demonstration of the unit operating I've connected the output to an oscilloscope so we can visually see it we're now looking at the RF output on band C at approximately 1 megahertz as we can see it's pretty close to a pure sine wave on the higher frequencies it was actually desired that unit was not a pure sine wave so that it could produce harmonics above the fundamental frequency beyond 100 megahertz the coarse and fine attenuator controls adjusts the output level if we switch to band D the output goes to about 3.2 megahertz if we switch the mode to modulated RF we can see the amplitude modulated signal now we can see the output signal is amplitude modulated at 400 Hertz it can be also modulated by an external audio input switching to the AF output we can see the 400 Hertz sine wave output closer to 330 Hertz on this particular unit the output level is adjustable and goes up to approximately 14 volts RMS without a load this signal is useful for testing the audio stages of a radio receiver or amplifier for example I obtained this unit in 2013 from another local amateur radio operator it was in good condition and did not need any adjustments to the alignment it came with an original manual for the IG 102's laboratory version rather than the standard IG 102 since my unit is an IG one or two it could not have been the original manual for this unit it has the original microphone type connectors in a cable which appears to be original for the price the IG 102 was a good value in a small reliable generator with basic features needed for applications like radio receiver testing and alignment and Heath get sold many of them over the years the IG 102 is one of the pieces of test equipment described in my new book classic Heathkit electronic test equipment the book covers Heath kits test equipment starting with a brief history of Heath kit and overview of the test equipment product lines and tips on buying and restoring vintage test equipment from sources like eBay separate chapters cover the major categories of component testers and substitution boxes frequency counters meters oscilloscopes power supplies signal generators tube testers and checkers and miscellaneous test equipment each chapter includes one or more in-depth sections that look at a representative model from my Heath kit collection covering its features operation and notable quarks or trivia the appendix provides a list of references and resources including books websites and suppliers of parts manuals and related products and services as well as a detailed product listing of every known model of test equipment produced by Heath kit thanks for watching if you enjoyed this video please check out my other YouTube videos on vintage amateur radio and test equipment

Channel: Jeff Tranter

Views: 20,072

Rating: 4.9391637 out of 5

Keywords: Heathkit, Signal Generator, Test Equipment, Electronics

Id: wtdJt13i7nA

Length: 9min 12sec (552 seconds)

Published: Sat Nov 02 2013