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Author Topic: Drake TR7 - Tx Foldback Circuit?  (Read 3546 times)
K6HOM
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Posts: 16




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« on: September 14, 2011, 08:35:26 AM »

Hi All,

I will be very grateful if anyone could help me with this question, please.  In reading through the TR7 manual, no mention is made of a "foldback" circuit in the transmitter section, i.e. protection from high SWR.  I do not have a schematic of this tranceiver to determine if such a circuit exists and I am curious.

Thank you for any help that you can provide!

73,

Rick
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AC5UP
Member

Posts: 4546




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« Reply #1 on: September 14, 2011, 08:55:26 AM »

Here's the schematic: http://www.wb4hfn.com/DRAKE/DrakeManuals/PDFDOCS/TR7-Circuit-Diagrams.pdf

And the web site it came from: http://www.wb4hfn.com/DRAKE/DrakePageHome.htm

Might want to poke around the URL above as there's a fair amount of legend & lore on the TR7.

And while you're at it, visit here: http://www.alg.myzen.co.uk/radio/tr7/mods.htm
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WB2WIK
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Posts: 21837




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« Reply #2 on: September 14, 2011, 11:34:16 AM »

The TR-7 does have self-protecting "power foldback" circuits, but they're not nearly as "aggressive" as on the modern rigs.

The specific ratings for this are shown at the lower right corner of the back side of the TR-7 brochure, which is here: http://wb4hfn.com/DRAKE/DrakeCatalogsBrochures/Brochure_TR7_04B.htm

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K6HOM
Member

Posts: 16




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« Reply #3 on: September 15, 2011, 09:55:12 AM »

Thank you for your help, AC5UP and WB2WIK!  Hope to return the favors someday.

Best,

Rick
 
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