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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W3UTD on January 25, 2010, 04:11:52 PM



Title: Ranger Bandswitch
Post by: W3UTD on January 25, 2010, 04:11:52 PM
Thanks to Rodger, WQ9E, I now have a replacement rear band switch SW3B (after crushing the original  :-[)

I need one last piece of help.  I can't figure out the correct orientation for the rotating part

Here it is, chassis upside down
(http://www.quasc.com/ebay/view.jpg)
matching this figure from the assembly manual
(http://www.quasc.com/ebay/assy.jpg)
but with the band switch in the 160M position, I have two choices for the rotating piece, A or B
A(http://www.quasc.com/ebay/orientationA.jpg) or B (http://www.quasc.com/ebay/orientationB.jpg)

What's worse, is that the schematic has them shown upside down, and my head is about to burst!


Title: Re: Ranger Bandswitch
Post by: WQ9E on January 25, 2010, 05:22:00 PM
Fraser,

You want to go with your photo A.  The switch will then gradually short out additional sections of tank coil L11 as you rotate to the higher frequency bands.

You can double check and follow this by making sure that contact 10 is connected to the end part of L11 that connects to the variable coupling capacitor C9.  As you rotate the switch to 80 meters, then it shorts out part of the coil and as you continue rotating to the higher bands it will short out more sections of L11.

Glad the switch made it in one piece!

Rodger


Title: Re: Ranger Bandswitch
Post by: WD5JKO on January 25, 2010, 05:42:27 PM

Fraser,

   Part of what I do professionally is Technical Support pertaining to multi-million dollar machines used in the wafer fab business. Many times I am given just a sliver of information, and between the delays to/from other time zones, and political pressure, I sometimes have to hop on a plane to tackle an issue.

   So why am I boring everybody with what I do? Well I was so impressed with your post on that ceramic switch. You researched the problem, and presented the issue in such a way that Rodger had no trouble answering your question. In industry, we waste so much time and money over issues like this that it is just incredible. So again what a remarkable job you did presenting the problem such that those who understand the Ranger transmitter will have little trouble giving you sound advice.

   Good Luck with that Ranger.. ;D

Jim
WD5JKO


Title: Re: Ranger Bandswitch
Post by: W3UTD on January 25, 2010, 05:59:59 PM
My engineering education (Aerospace) sometimes can be put to good use!


Title: Re: Ranger Bandswitch
Post by: W3UTD on January 25, 2010, 10:13:25 PM
It's alive .... it's alive ...
(http://www.quasc.com/ebay/itsalive.jpg)

I've a got carrier on my receiver.  The meter lights up, but there's no needle movement.  Enough for tonight, time for a celebratory drink!


Title: Re: Ranger Bandswitch
Post by: WQ9E on January 25, 2010, 10:31:08 PM
I see the light!  Congratulations.  Hopefully the meter problem is just one of the leads is loose on the back of the meter.



Title: Re: Ranger Bandswitch
Post by: W3UTD on January 25, 2010, 10:57:18 PM
Ha!  A non-existent connection between the meter and terminal 12 of the meter switch.  The terminal looks like it never had solder on it.  How did it ever work?


Title: Re: Ranger Bandswitch
Post by: WQ9E on January 26, 2010, 08:37:20 AM
I am glad the meter was a quick and cheap fix!

When I finished restoring my Hallicrafters SX-88 it worked fine except for an intermittent crackle on the highest frequency range.  I traced it down to a wire passed through a terminal of the mixer coil but never soldered.  Even though there was no solder it did have the same little dot of red inspection paint that was on all of the other connections.

This receiver was one of 4 that belonged to Bob Denniston W0DX and I know that he regularly used all 4 of the receivers.  The mechanical connection must have been sufficient for years but during either transport or restoration it became loose enough to cause trouble.

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