Plan to convert the IG-102 Signal Generator to solid state
A search for "IG-102" on this very handy site by Mike Yancey:
https://mikeyancey.com/73mag/index.php
revealed an article by Julian Rossnick in 73 Magazine for May 1978:
https://archive.org/details/73-magazine-1978-05/page/120/mode/1up?view=theater
the article is also available here:
https://www.nostalgickitscentral.com/heath/73-index/articles/IG-102%20Goes%20Transistor-5-78.pdf
Perfect ! The article modifies the IG-102 by using 4 JFETs to take the place of the two tubes. The power supply is disconnected and a battery can be used OR the filament supply can be modified to produce low voltage DC. Two resistors are added to the circuit. A very (hopefully) easy mod !
Interestingly the article specifies the transistors as either Calectro K 4-634 (Calectro supplied carded components to TV repair shops and small electronic retailers)
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| a different part, found on ebay: https://www.ebay.com/itm/204743838552 |
OR the article mentions an 8 FET transistor assortment from Radio Shack 276-1623. Neither is available on Ebay (it has been 46 years :) but an old Radio Shack 1977 catalog comes to the rescue with part numbers:
BTW, 276-1623 inflates to:
Checking on transistor availability in 2024: one transistor mentioned in the article:
2n5951 not at Mouser
mentioned in the Radio Shack 1977 catalog, page 92 for 276-1623:
2n4859 not at Mouser
2n3970 in stock Mouser but too expensive $10.92
3n201 MOSFET
2n5460 not at Mouser
2n3819 bingo ! in stock at Mouser but not too expensive at $1.12 (about the 1977 price inflated):
The 2n3819 has a gate in the middle pinout which should work well for the plate-grid-cathode pinout of the three triodes in the IG-102. The 2n3819 was also used by W1FB and others in QST articles, for example this dip meter by W6HPH, March 1980 page 11:
https://webpubs.arrl.org/pubs_archive/74121
Next step: order parts !
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
