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Hi All,

Are there 2 versions of the TX Exciter board in the TR7? My one doesn't seem to be quite the same as the picture in the service manual.

Thanks for your help...

-- 
From Dave Cutts G4FAW 73s

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The answer is yes. ?Rob, NC0B

Thanks Rob,any idea where I can get details of it? my manual only shows one version, Its very similar...

Thanks Dave G4FAW

I suspect the difference is largely cosmetic. Drake started using boards with solder mask in later years. These will have a green coloring while earlier boards are bare tinned copper. A surf of eBay offerings confirms this. Other than the solder mask and packaging of some components they look pretty much the same.





73

-Jim
NU0C

On Fri, 10 Mar 2023 06:34:46 -0800
"Dave Cutts via groups.io" <g4faw@...> wrote:

Thanks Rob,any idea where I can get details of it? my manual only shows one version, Its very similar...

Thanks Dave G4FAW

Decades ago on a mobile trip from CO to ME my TR-7 quit transmitting. I was in Ohio so Drake replaced the driver board. I think there was a significant upgrade to the replacement board. Rob, NC0B

I think your answer can be found here -

http://www.wb4hfn.com/DRAKE/DrakeArticles/TR7_Comparison_Article/TR7_Idenity-04.htm

Doug, WA3DSP

Well, no. That is the Predriver board, which did have a major change. The Transmit Exciter board is where the mic amp, PTT/VOX, and balanced modulator live.

73
-Jim
NU0C

On Fri, 10 Mar 2023 12:14:29 -0800
"Doug Crompton WA3DSP" <wa3dsp@...> wrote:

I think your answer can be found here -



Doug, WA3DSP

Yes, there was to the Predriver board. The Transmit Exciter is a completely different board. Both Predriver version are covered in the service manual.

73

-Jim
NU0C

On Fri, 10 Mar 2023 19:21:18 +0000
"Rob Sherwood" <rob@...> wrote:

Decades ago on a mobile trip from CO to ME my TR-7 quit transmitting. I was in Ohio so Drake replaced the driver board. I think there was a significant upgrade to the replacement board. Rob, NC0B

On Mar 10, 2023, at 11:21 AM, Jim Shorney <jimNU0C@...> wrote:

?
I suspect the difference is largely cosmetic. Drake started using boards with solder mask in later years. These will have a green coloring while earlier boards are bare tinned copper. A surf of eBay offerings confirms this. Other than the solder mask and packaging of some components they look pretty much the same.





73

-Jim
NU0C

On Fri, 10 Mar 2023 06:34:46 -0800
"Dave Cutts via groups.io" <g4faw@...> wrote:

Thanks Rob,any idea where I can get details of it? my manual only shows one version, Its very similar...

Thanks Dave G4FAW

Yep, mine is a later one with split rear panel and green solder screen on the boards.. The component position of the Mic input resistors is slightly different. Anyway, found a cracked resistor (150k) on the Mic input circuit...

Nice catch. Those 1/4 Watt carbon comp resistors that Drake used seen prone to that.

73

-Jim
NU0C

On Sat, 11 Mar 2023 06:22:00 -0800
"Dave Cutts via groups.io" <g4faw@...> wrote:

Yep, mine is a later one with split rear panel and green solder screen on the boards.. The component position of the Mic input resistors is slightly different. Anyway, found a cracked resistor (150k) on the Mic input circuit...