{"id":3428,"date":"2024-01-27T07:23:48","date_gmt":"2024-01-27T15:23:48","guid":{"rendered":"https:\/\/philcoradio.com\/library\/?page_id=3428"},"modified":"2024-01-27T07:23:48","modified_gmt":"2024-01-27T15:23:48","slug":"philco-model-38-690-repairs-part-12","status":"publish","type":"page","link":"https:\/\/philcoradio.com\/library\/index.php\/shop-talk\/rons-radios\/philco-model-38-690-repairs-part-12\/","title":{"rendered":"Philco model 38-690 Repairs \u2013 Part 12"},"content":{"rendered":"

\"A<\/p>\n

Before proceeding to partially disassemble this Philco 38-116 chassis in order to partially rebuild it as a test jig for Philco RF units, I felt that I really needed to draw out what I wanted to do.<\/p>\n

I began with a stock Philco 38-116 Code 121 schematic. The 38-116 Code 121 was originally made for use with the 37-116 RF unit. See below.<\/p>\n

\"Diagram,<\/p>\n

Stock Philco 38-116 Code 121 schematic. Click to see an enlarged version.<\/em><\/p>\n

Using my old standby paint program \u2013 a 24-year-old version of Paint Shop Pro, Version 4.14 \u2013 I began to make changes to the 38-116-121 schematic, highlighting portions of the schematic I would not be using for the test jig. When finished, it looked as it does below.<\/p>\n

\"Diagram,<\/p>\n

Philco 38-116 Code 121 schematic, with my proposed modifications. Portions of the circuitry I will not be using is in red. Click to see an enlarged version.<\/em><\/p>\n

As you will see by looking over my modified schematic, I intend to take off the audio signal at the radio\u2019s volume control. Therefore I will not be using the audio preamp or output circuitry, and will also not need the set\u2019s speaker (I do not have one anyway). I will have to come up with a substitute for the 350 ohm speaker field coil, but that will be simple \u2013 I will use a power resistor instead.<\/p>\n

\"A<\/p>\n

Philco 38-116-121 chassis, now ready for a partial rebuild.<\/em><\/p>\n

Now, with my new schematic, I proceeded to remove a few more components from the chassis. It is now ready to be rebuilt.<\/p>\n

In my next installment, I will start rebuilding the chassis and begin getting it ready for use as a test jig for Philco RF units.<\/p>\n","protected":false},"excerpt":{"rendered":"

Before proceeding to partially disassemble this Philco 38-116 chassis in order to partially rebuild it as a test jig for Philco RF units, I felt that I really needed to draw out what I wanted to do. I began with a stock Philco 38-116 Code 121 schematic. The 38-116 Code 121 was originally made for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2599,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3428","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/comments?post=3428"}],"version-history":[{"count":1,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3428\/revisions"}],"predecessor-version":[{"id":3433,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3428\/revisions\/3433"}],"up":[{"embeddable":true,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/2599"}],"wp:attachment":[{"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/media?parent=3428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}