[Drake] R7 Help......

[N5ARW]

Scott,

1) In test mode my R-7 settles out at 18.03 on the lower bands and 33.29 on
21
When you switch bands the initial frequency is set in the digital control
circuitry by reading the band switch and then modified by the up-down push
buttons.  You didn't mention deox'ing the band switch so i would give that
some attention. .  Looking at page 2-7 of the SM you can also see a mapping
of the signal levels from the switch to the PROM outputs so you can check
the switch contact levels.  Since 23 Mhz is out of range for the 21 Mhz
position that might be a good place to start.

2) You can get a "recreated" TR-7/R-7 service kit from WB4HFN
http://www.wb4hfn.com/Services/W7AVK/tr7ext2.htm which includes the
extenders and digital jumper board you need to service this radio.  Its a
good investment.

Good luck

73
James N5ARW

On Sat, Aug 20, 2016 at 8:45 PM, Ka9p--- via Drake <drake at mailman.qth.net>
wrote:

>
> I'm looking for a good R7 mechanic or advice re same.
>
> My R7 wants to start up at 23 mhz when switched to 21 mhz, and the three
> low frequency bands, LF and AM broadcast, also want to start a few mhz
> higher than they should.
>
> I've reseated and deoxited all the pins on the boards.
>
> The service manual describes a self test where you throw the  FIXED switch
> to let the VCO free run and settle out, in one case at about  17 mhz, and
> in
> the other at about 32 mhz if the VCO is properly adjusted.
>
> When I do this test, the VCO settles out at 18 and 34 mhz
> respectively....although I'm not sure if 17 is about 18 or if 32 is about
> 34 for  the
> purposes of the self test - no further info in the manual re that, other
> than the
> alignment instructions if it's not.
>
> To do the alignment the DR7 board has to be removed, and a header installed
>  to allow access to the board with the required VCO adjustment slugs.
>
> So if anyone has any idea about any of the following issues, I'd be in your
>  debt for your thoughts.
>
> 1) whether 17=18 and 32=34 mhz for the self test
>
> 2) where on might beg, steal borrow or find parts to make up the required
> header for alignment of the VCO
>
> 3) where there's a great R7 mechanic that does this, still; and
>
> 4) if that fault looks familiar and it might be something else, what it
> might be.
>
> Really appreciate input on any of that !
>
>
> Thanks, alot,
>
> Scott  ka9p
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-- 
James True N5ARW
www.boatanchor.com