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Nathan's 37-690X
#30

RF Subchassis Recap

Most of the capacitors are more or less accessible without taking the sections completely apart. Unfortunately there are two capacitors buried in the antenna and RF sections that are entirely inaccessible.
I didn't see a way to replace them otherwise.

[Image: https://farm2.staticflickr.com/1870/4452...89bd_c.jpg]

[Image: https://farm2.staticflickr.com/1893/4457...7935_c.jpg]

So here we go!

[Image: https://farm2.staticflickr.com/1855/4452...caf8_c.jpg]

[Image: https://farm2.staticflickr.com/1896/4457...9c83_c.jpg]

In order to lift a given section out it's necessary to first desolder it from the tuning capacitor:

[Image: https://farm2.staticflickr.com/1849/4386...3b76_c.jpg]

Here's a sense of how deep these things are inside of the wafer band switch. Ugh.

[Image: https://farm2.staticflickr.com/1881/4276...3376_c.jpg]

[Image: https://farm2.staticflickr.com/1891/4276...7cb1_c.jpg]

The end of the capacitor has very little lead and there's almost no room to get a soldering iron in (and mind the very fragile wires coming from the coils!).

I finally managed to replace the buried capacitor in both sections.

[Image: https://farm2.staticflickr.com/1883/3070...4e42_c.jpg]

Range 2 Antenna Coil

Unfortunately I did notice this broken wire on the Range 2 Antenna coil as I was buttoning things back up.  Icon_sad

[Image: https://farm2.staticflickr.com/1867/4276...2f72_c.jpg]

At first I was sure that I must've broken it - but I noticed something else - the screw holding that coil in place was missing.
You can see the new screw that I put there in the picture below:

[Image: https://farm2.staticflickr.com/1892/3070...b7c6_c.jpg]

Maybe it shook loose and the wire was already broken?
Maybe it was broken long ago by someone else?
I'd like to believe that anyway.  Icon_lol

The remaining wire was very fine and fairly brittle. It's also has a cloth covering near the coil which I tried - but ultimately failed - to strip and solder a new wire to.  Icon_e_sad

Oh well - not much I can do about it now. And let's face it - band 2 is often dead on these models due to the oscillator coil failing.  I just hope the broadcast band coils are intact.
I marked where the connection should be below. Unless someone has a clever idea for how to salvage it I'll just leave it be.

[Image: https://farm2.staticflickr.com/1873/4276...192a_c.jpg]


Messages In This Thread
Nathan's 37-690X - by Nathan Slingerland - 08-18-2018, 02:14 PM
RE: Nathan's 37-690 - by Nathan Slingerland - 08-18-2018, 02:30 PM
RE: Nathan's 37-690 - by Nathan Slingerland - 08-18-2018, 02:40 PM
RE: Nathan's 37-690 - by Kenradio - 08-18-2018, 04:02 PM
RE: Nathan's 37-690 - by Nathan Slingerland - 08-18-2018, 08:54 PM
RE: Nathan's 37-690 - by Nathan Slingerland - 08-18-2018, 09:03 PM
RE: Nathan's 37-690 - by morzh - 08-18-2018, 10:00 PM
RE: Nathan's 37-690 - by Nathan Slingerland - 08-19-2018, 01:02 AM
RE: Nathan's 37-690 - by Arran - 08-19-2018, 01:52 AM
RE: Nathan's 37-690X - by klondike98 - 08-21-2018, 11:39 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-21-2018, 10:09 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-21-2018, 10:52 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-22-2018, 08:09 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-22-2018, 09:17 PM
RE: Nathan's 37-690X - by Ron Ramirez - 08-22-2018, 09:31 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-22-2018, 11:30 PM
RE: Nathan's 37-690X - by Radioroslyn - 08-22-2018, 11:31 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-22-2018, 11:33 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-23-2018, 12:12 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-23-2018, 12:30 AM
RE: Nathan's 37-690X - by morzh - 08-23-2018, 08:08 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 08-25-2018, 11:25 PM
RE: Nathan's 37-690X - by Arran - 08-26-2018, 12:33 AM
RE: Nathan's 37-690X - by Ron Ramirez - 08-26-2018, 07:59 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-08-2018, 09:10 AM
RE: Nathan's 37-690X - by klondike98 - 09-08-2018, 11:00 AM
RE: Nathan's 37-690X - by GarySP - 09-08-2018, 11:40 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-09-2018, 11:42 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-09-2018, 11:56 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-09-2018, 04:43 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-12-2018, 09:52 PM
RE: Nathan's 37-690X - by morzh - 09-12-2018, 10:35 PM
RE: Nathan's 37-690X - by thirtiesradio - 09-13-2018, 01:32 AM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-13-2018, 10:01 PM
RE: Nathan's 37-690X - by morzh - 09-13-2018, 10:37 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-13-2018, 10:53 PM
RE: Nathan's 37-690X - by Radioroslyn - 09-13-2018, 11:16 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-13-2018, 11:33 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 09-23-2018, 09:20 PM
RE: Nathan's 37-690X - by Nathan Slingerland - 10-06-2018, 09:28 PM
RE: Nathan's 37-690X - by klondike98 - 10-07-2018, 10:02 AM
RE: Nathan's 37-690X - by morzh - 10-07-2018, 01:37 PM



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