On Dec 28, 2024, at 8:28?PM, Tony N5DIM <tony@...> wrote:

The WB4HFN website has a section with great information related to that power supply board. I just used it to resurrect a TR7 that was DOA. Good luck. 73 Tony N5DIM?

On Dec 28, 2024, at 5:52?PM, Gary Follett via groups.io <xntrick1948@...> wrote:

?Sounds like you are on the right track. Don’t ocelot the electrolytic capacitors on that supply as well.

Gary

W0DVN

On Dec 28, 2024, at 6:12?PM, Jim Harris via groups.io <radiove1rb@...> wrote:

Gary, I found a few minutes to work on the TR7 and discovered that the high VCO is not working at all. It does have the 10 vdc supply switch?on it but I don't know if that reulagor?is working or not. I will check it out but have to work on getting the metal shield off. I Hope that is the problem but I will work on it maybe tomorrow. Thanks for all your help.

73, Jim VE1RB

On Fri, Dec 27, 2024 at 9:06?PM Gary Follett via??<xntrick1948=[email protected]> wrote:

It is worth asking, did the failure of your VCO board (displaying 51.950) occur on its own? That is to ask, did the radio work properly and then just fail or has it, as long as you have had it, always operated with this fault??

If it once worked for you and then failed, then it would make sense to see what gets disconnected if those pins are not in line ?and look for a way that same thing could happen without the pin alignment problem.

The pin alignment fix is pretty easy though, if the board alignment is the cause. It just SOUNDS difficult.

That whole DR7 was always a source of issues due to its complexity and difficulty of installation. I don’t know how a DR7 could even endure the stresses of removal and reinsertion more than once!

Gary?

W0DVN

On Dec 27, 2024, at 6:25?PM, Jim Harris via??<radiove1rb=[email protected]> wrote:

Thanks Tom. I printed that off but hope that is not the problem.

73, Jim VE1RB

On Fri, Dec 27, 2024 at 8:05?PM Tom Evans via??<Tom.AG9X=[email protected]> wrote:

In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0 on the old retired Drakelist.

The thread is archived at?

Please click the link so the owner knows that we find the archive useful.

Hope this helps.

Tom, AG9X

================?

Below are the posts from Brian Koontz WA3ITE, Jim Shorney NU0C and Garey Barrell K4OAH (SK)?

(just in case Drake TR-7 DR-7 problems outlive the??site)

Re: [Drakelist] Almost there: TR-7 display issues -- FIXED!

Brian Koontz Fri, 30 Jul 2010 20:36:54 -0700

Well, the TR-7 from hell is now a fully operational TR-7 from hell!

In preparation for some signal tracing, I decided to extend the DR-7
board using the extenders I have.? To do this, you have to unmount the
two voltage regulators mounted to the chassis, and jumper the
connector farthest to the right. ?(I didn't bother connecting the
up/down band buttons.) ?Lo and behold, the display worked!?

Some further investigation revealed that the chassis has warped over
the years, so the two 3-prong connectors on the VCO board were no
longer in a horizontal line.? So I was determined to make sure the
board was fully seated on all the connectors.

To do this, I had to drop the front panel.? Not a major chore, just
one knob to remove (the band knob) and 6 side screws. With that now
out of the way, it was an easy job to determine if all the pins were
where they belonged.? The only snag was that the front panel, when
canted downwards, angles the PTO can upwards.? So you have to hold the
front panel perpendicular and steady with slight downward pressure to
fully seat the board.? Once all the pins were visually confirmed to be
seated, I remounted the front panel, reattached the regulators and all
the connectors, and fired the rig up.? Everything now seems to work!

It turns out the original DR-7 board was indeed defective as well
(possibly because it had been seated incorrectly).? And a visual
confirmation from topside indicates the chassis is, indeed, warped:
The screw hole is misaligned with the mounting hole in the board.?

So, for archival purposes in case anyone else decides to search for
this problem: ?If the display if fixed on "51950", one possible cause
is that one or more DR-7 pins, possibly the VCO pins, are not
correctly seated.? The best solution is to drop the front panel and
confirm visually that the pins are fully seated.

Now it's time to get on the air!

??--Brian/WA3ITE

=================?

Jim Shorney Fri, 30 Jul 2010 23:17:58 -0700

On Fri, 30 Jul 2010 20:40:52 -0500, Brian Koontz wrote:

>Well, the TR-7 from hell is now a fully operational TR-7 from hell!
>
>Now it's time to get on the air!

Congratulations, Brian! You have been assimilated into the collective.
Resistance is futile.

73

-Jim

=================

?

Garey Barrell?k4oah@...?via?
Sat, Jul 31, 2010, 8:34?AM
to drakelist


Brian Koontz wrote:
> Some further investigation revealed that the chassis has warped over
> the years, so the two 3-prong connectors on the VCO board were no
> longer in a horizontal line.? So I was determined to make sure the
> board was fully seated on all the connectors.
>
>
>
> So, for archival purposes in case anyone else decides to search for
> this problem: ?If the display is fixed on "51950", one possible cause
> is that one or more DR-7 pins, possibly the VCO pins, are not
> correctly seated.? The best solution is to drop the front panel and
> confirm visually that the pins are fully seated.
>

Brian -

Congratulations!! ? It's always nice when one 'comes together'.

Just as an aside, someone suggested earlier (and correctly) that the
"51950" problem may indicate a loss of the 500 kHz reference signal.?
You might find it interesting that the left-most three pin connector on
the VCO board is the 500 kHz reference signal!

Those pins on the bottom of the DR-7 are ALWAYS a problem, ya' just
can't see 'em!!

Your 'trials' have been an interesting 'trip' for others, thanks for
documenting it for us all.


73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line& ?TR-4/C Service Supplement CDs
<>

=================

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Search terms to make this post easier to find:? Drake TR-7 TR7 DR-7 DR7 display frozen locked stuck ? 51950?? 51,950?? 51 950?? 5195? 51950.0 ? 51,950.0 ? 51 950 0

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