{"id":3893,"date":"2024-02-11T09:45:12","date_gmt":"2024-02-11T17:45:12","guid":{"rendered":"https:\/\/philcoradio.com\/library\/?page_id=3893"},"modified":"2024-02-11T09:45:12","modified_gmt":"2024-02-11T17:45:12","slug":"philco-model-90-restoration-part-4","status":"publish","type":"page","link":"https:\/\/philcoradio.com\/library\/index.php\/shop-talk\/rons-radios\/philco-model-90-restoration-part-4\/","title":{"rendered":"Philco model 90 Restoration \u2013 Part 4"},"content":{"rendered":"

<\/p>\n

The 0.1 uF, 630 volt film capacitors arrived soon enough from Mouser Electronics, and I was then able to rebuild the last bakelite block capacitor which used two of them. Afterwards, I installed the final dogbone resistor. At this point, the chassis looked as shown in the photo above.<\/p>\n

I thought this might be a good time to perform some preventive maintenance to the set\u2019s volume control.<\/p>\n

<\/p>\n

The Philco 90 volume control.<\/em><\/p>\n

Notice that a warning is printed on the metal cover of the control, DO NOT REMOVE COVER. Of course, I paid no attention to the warning, as I knew this control was long overdue for a good cleaning.<\/p>\n

It was not difficult to pry the cover free from the back of the control, since I had left the control bolted to the front of the chassis.<\/p>\n

<\/p>\n

The cover is removed from the volume control for likely the first time in 92 years.<\/em><\/p>\n

Once I removed the cover, I noticed a date had been stamped on the inside \u2013 AUG 26 1931. This is likely the date the control had been manufactured.<\/p>\n

Did you also notice that this control was manufactured by CTS in Elkhart, Indiana (which is in far northern Indiana, on the opposite side of the state from where I live)?<\/p>\n

<\/p>\n

A date of \u201cAUG 26 1931\u201d was stamped on the inside of the volume control cover.<\/em><\/p>\n

With the cover removed, the control was sprayed sparingly with a dose of DeoxIT FaderLube. Notice that I specifically said \u201cFaderLube\u201d. The product is now called \u201cDeoxIT Fader F-Series.\u201d (My can of the product is older, so it has a \u201cFaderLube\u201d label.) I mention this because it is important that potentiometers in vintage radios are cleaned with FaderLube\/Fader F-Series, and not DeoxIT D5. The D5 product can permanently damage potentiometers by removing carbon from the control. The control depends on having a deposit of carbon to control the particular radio circuit (volume or tone) and without the carbon, the control is rendered useless.<\/p>\n

Rule of thumb:<\/p>\n

Use DeoxIT D5 for switches.<\/p>\n

Use DeoxIT FaderLube\/Fader F-Series for carbon (and plastic) potentiometers.<\/p>\n

This document<\/a> from Caig<\/a>, the manufacturer of DeoxIT, explains which of their products is suitable for certain applications.<\/p>\n

Anyway, once the FaderLube was applied to the control, I rotated the control through its range approximately 50 times to allow the product to clean and lubricate the control. After this, the control was much easier to turn.<\/p>\n

I finished this portion of the job by carefully pressing the back cover back onto the control.<\/p>\n

Next, I decided to go ahead and install new rubber grommets for the tuning condenser. The originals were two-piece units which were installed from the top and the bottom of the chassis.<\/p>\n

<\/p>\n

New rubber grommets for the tuning condenser.<\/em><\/p>\n

These grommets, as you can see above, are one-piece instead of two-piece. This means that once they are in place, I will not have to worry about trying to keep the grommets in place while reinstalling the tuning condenser.<\/p>\n

They are also a harder rubber than the original gum rubber washers. You can obtain original style gum rubber washers from Renovated Radios<\/a>. The only reason I did not use their grommets is because (a) the ease of installation of the tuning condenser using single piece grommets, and (b) I happened to have a number of these grommets, having purchased a large supply of them some time ago from McMaster-Carr.<\/a><\/p>\n

<\/em><\/p>\n

The new grommets are now in place on the chassis.<\/em><\/p>\n

The McMaster-Carr single-piece grommets are difficult to install, but with some patience and perseverance, the job was completed in a reasonable length of time.<\/p>\n

These grommets are not quite tall enough to hold the tuning condenser at the proper height. I had planned for this when I bought the grommets by also purchasing several flat rubber washers, also from McMaster-Carr.<\/a><\/p>\n

<\/p>\n

Rubber washers about to be glued on top of the grommets.<\/em><\/p>\n

Using super glue, the washers were quickly glued to the tops of the grommets. Now, when I am ready to reinstall the tuning condenser, it will ride at its original factory height.<\/p>\n

<\/p>\n

Rubber washers are now glued to the grommets.<\/em><\/p>\n

<\/p>\n

Another view of the grommets with the washers glued to the top of each.<\/em><\/p>\n

I was not quite ready to reinstall the tuning condenser, though, as I still had some more work to do under the chassis. I will have to tell you what else I did to the 90 chassis in the next installment, though, as we are all out of space for this time. Please join me next time for more.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

The 0.1 uF, 630 volt film capacitors arrived soon enough from Mouser Electronics, and I was then able to rebuild the last bakelite block capacitor which used two of them. Afterwards, I installed the final dogbone resistor. At this point, the chassis looked as shown in the photo above. I thought this might be a […]<\/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-3893","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3893","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=3893"}],"version-history":[{"count":1,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3893\/revisions"}],"predecessor-version":[{"id":3958,"href":"https:\/\/philcoradio.com\/library\/index.php\/wp-json\/wp\/v2\/pages\/3893\/revisions\/3958"}],"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=3893"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}