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I had a TR7 about 15 years ago and loved it but I sold it to help finance my K3 purchase, which I also love and still have.? I acquired a TR7 today from an estate today with the PS7.? It's S/N 2713. The thing was pretty dirty and will need a case repainting but seemed OK otherwise and the price was right.? Here's what I have gleaned so far:

1.? The PS7 doesn't work.? I hear the transformer thunk when I turn on the rig and the fans on the PS and TR7 both come on but nothing else.? The fuse is good and not blowing so I'll need to fix that at some point.
2.? The rig came on fine with a different PS and seems to RX and TX fine but power out was around 170 watts and the ALC light was not coming on.? I adjusted the control on the ALC board to about 150 watts on 20M at full drive and the ALC light now works but stays on no matter how low I adjust the drive.? I know there's another adjustment for that on 10M on a diffferent board but I haven't gotten to that yet.? Power doers adjust down to zero now.
3.? The S-meter reads very low but signals sound fine so guess that's another adjustement I need to make.? Forward and reflected hardly move the meter and adjusting the controls by the antenna socket make no difference.
4.? Some good news is that all 4 filter slots are full which is great news for a CW op like me.
5.? There's a big change in noise between USB and LSB looks like carrier balance is off.
6.? The sidetone volume level is very low, I have to turn the volume control way up to hear it.

I do have a PDF copy of the service manual.? The big question is will I need the board extenders to fix all this and properly align the rig?? If so wheer can I find some that won't cost me too much?

My apologies in advance for the many stupid questions I'm sure I will ask as this project moves foward!

73, Bill NZ0T

Bill,

Welcome back to the Drake world! Comments inserted below.

On Thu, 08 Feb 2024 14:49:51 -0800
"Bill NZ0T" <nz0tham@...> wrote:

I had a TR7 about 15 years ago and loved it but I sold it to help finance my K3 purchase, which I also love and still have.? I acquired a TR7 today from an estate today with the PS7.? It's S/N 2713. The thing was pretty dirty and will need a case repainting but seemed OK otherwise and the price was right.? Here's what I have gleaned so far:

1.? The PS7 doesn't work.? I hear the transformer thunk when I turn on the rig and the fans on the PS and TR7 both come on but nothing else.? The fuse is good and not blowing so I'll need to fix that at some point.

Check the 4-pin Jones plug. You may have oxidation on the contacts. Maybe also the regulator board and the connector for the pass transistor driver. I had one that was moused and the connector contacts had corroded to nothing. You have the optional fan on the PS so the main filter caps are probably OK. They are mostly for the the thunk.

2.? The rig came on fine with a different PS and seems to RX and TX fine but power out was around 170 watts and the ALC light was not coming on.? I adjusted the control on the ALC board to about 150 watts on 20M at full drive and the ALC light now works but stays on no matter how low I adjust the drive.? I know there's another adjustment for that on 10M on a diffferent board but I haven't gotten to that yet.? Power doers adjust down to zero now.

You may have a PA deck oscillation issue. Go back to it after you have cleaned up the connectors and check again.

3.? The S-meter reads very low but signals sound fine so guess that's another adjustement I need to make.? Forward and reflected hardly move the meter and adjusting the controls by the antenna socket make no difference.

If the rig has been sitting idle in a time and is dirty you may have connector oxidation issues, otherwise known as Molexia. Often just pulling and re-seating the boards will resolve strange problems. You may need to clean the connectors with DeOxit or equivalent.

4.? Some good news is that all 4 filter slots are full which is great news for a CW op like me.
5.? There's a big change in noise between USB and LSB looks like carrier balance is off.

Fixed Passband adjustments on the power supply board in the front right corner of the radio. They are very easy to bump and will go off if you so much as breathe on them. It is likely the radio will benefit from a full frequency alignment once you get it cleaned up, but your USB/LSB issue is the pots. A popular mod is to upgrade them all to 10 turn trimpots. While you are there, replace C2108 on the power supply board. It is running on borrowed time.

6.? The sidetone volume level is very low, I have to turn the volume control way up to hear it.

Again, probably Molexia. The sidetone comes from a sample of the CW oscillator fed into the product detector. It should be loud and the only level control is your volume control.

I do have a PDF copy of the service manual.? The big question is will I need the board extenders to fix all this and properly align the rig?? If so wheer can I find some that won't cost me too much?

Probably not. I have a set but I can count on one hand and have fingers left over the number of times I have used anything other than the Jumper board. They show up on eBay once in a while and there have been aftermarket clones produced as well. Not cheap. The service manual is your friend. The how stuff works sections are very good.

My apologies in advance for the many stupid questions I'm sure I will ask as this project moves foward!

By all means, ask. We don't bite.

--

73

-Jim
NU0C

Could somebody please point me towards a prodcedure for removing and cleaning the circuit boards?? I assume I will need to removw the display board to get to all the boards so I need to know how to do that too.? I have spent about an hour looking around on the internet and haven't found what I need yet and there is nothing in the service manual.

73, Bill NZ0T

On 2/8/24 21:36, Bill NZ0T wrote:

Could somebody please point me towards a prodcedure for removing and
cleaning the circuit boards?? I assume I will need to removw the
display board to get to all the boards so I need to know how to do
that too.? I have spent about an hour looking around on the internet
and haven't found what I need yet and there is nothing in the service
manual.

73, Bill NZ0T

The process for removing the DR7 board to get to the boards underneath
is in the service manual.? I'd have to look to see what page it's on. ?
It involves sliding the bandswitch shaft back and dropping the front
panel.? The DR7 board can be removed without doing all that, but some
frown on doing it.

When cleaning the Molex connectors; I do what Rob, NC0B, recommended
many years ago when I had an R7, that I wish I still had.? That is use
DeoxIT on a pipe cleaner to clean the female connectors. Install and
remove the boards a couple of times to clean the male connectors.

Hope that helps.


73

Stan
KM4HQE

To remove the DR7 (display) board remove the electrical connectors plugged in to the top side, the single screw, and unplug the coax and the wire that run to the High Pass Filter module. Hint: mark the hole that the coax feeds through with a marker, and leave the grommet on the wire with a knot tied in the wire so you don't lose it (don't ask how I know that). Then, starting from rear edge, work the DR7 up at an angle until all the connectors are free and pull it backwards until it clears the front panel. A classic PC slot cover is an ideal tool for this.

A more gentle but also more involved way to free the DR7 is to follow the procedure in the back of the service manual to gain access to the PTO. This will allow you to lift the DR7 straight up.

You can find instructions for a board puller for the circuit boards here:



This tool will fit into the small holes near the top edges of the boards.

Clean the connector male pins and sockets with your non-contaminating solvent of choice and follow up with a drop of DeOxit or equivalent (NOT spray). Installation is the reverse of removal. When re-installing the card cage cover shields all screws must be present, snug but NOT over-tightened.

Note that the coax connectors are a little odd. The center conductor of the coax is the "pin" and it slides into a tiny socket soldered to the board.

I am sure others will chime in with more tips.

73

-Jim
NU0C

On Thu, 08 Feb 2024 19:36:46 -0800
"Bill NZ0T" <nz0tham@...> wrote:

Could somebody please point me towards a prodcedure for removing and cleaning the circuit boards?? I assume I will need to removw the display board to get to all the boards so I need to know how to do that too.? I have spent about an hour looking around on the internet and haven't found what I need yet and there is nothing in the service manual.

73, Bill NZ0T

--

73

-Jim
NU0C

Sorry but I have to disagree in part with this. DeOxit is not appropriate for pots and there have been tales of it ruining the carbon track. It does not happen to everyone, but why chance it? Caig has a tool for pots called FaderLube.

73

-Jim
NU0C

On Fri, 9 Feb 2024 03:43:26 +0000 (UTC)
"Evan via groups.io" <k9sqg@...> wrote:

Sparingly applying DeOxit to switches and pots is a good idea too.

Thanks all for the tips, I got all the knobs off last night for cleaning.? Also gently pried the clear horizontal plastic covering the meter out of it's grooves because it is dirty on the inside.? I'll get those cleaned today.? Will also steal a coat hanger from one of the closets and make the board puller.

The inside of the rig is amazingly clean considering how filthy the exterior was lol.

73, Bill NZ0T

A lot of progress today. Got the knobs and front panel all cleaned up and put back on.? Gonna need to find some of the blue filter plastic for the VFO and meter lights but no hurry on that.? I took all the boards out and carefully cleaned the conenctions even tho they all looked relly clean.? This included taking the display board out which was a bit of a tussle but I managed to get it out, clean things up, and get it back in.? Still works too!

I managed to get the S-meter calibrated and it seems to be pretty accurate now.? Also got the mode frequency adjustments done in good shape. But the ALC adjustment did no go well.? R-1613 on the ALC board is very sensitive and adjusts from? almost 0 watts to 165 watts in a very short span.? The ALC light seems to go between staying on all the time no matter where the carrier level is set or not coming on at all.? Adjustment of R-2227 on the Predriver board seems to have no effect at all. The power meter calibration also won't worl.? Adjusting R-2001 and R-2002 has no effect at all.? Maybe that and the ALC problem are related?? The sidetone volume is still very low, haven't looked into that yet.

Messed with the PS7 a bit, it seems to be working fine with 13.6 volts measured inside it.? But when I plug in the Jones connector and turn on the rig the fans on the rig and PS come on (they are the original AC fans) but the rig doesn't power up.? I ran out of time so haven't opened up the Jones connector yet to look at it.? I haven't been able to find a pinout for the PS7 connector, anyone have that?

In good news the filter board is filled with the standard 2.3 filter, 1.8 SSB filter, 6.0 AM filter and 300 Hz CW filter!? And they all work just fine.

73, Bill NZ0T

Hi Bill,

On Fri, 09 Feb 2024 14:47:22 -0800
"Bill NZ0T" <nz0tham@...> wrote:

R-1613 on the ALC board is very sensitive and adjusts from? almost 0 watts to 165 watts in a very short span.? The ALC light seems to go between staying on all the time no matter where the carrier level is set or not coming on at all.? Adjustment of R-2227 on the Predriver board seems to have no effect at all. The power meter calibration also won't worl.? Adjusting R-2001 and R-2002 has no effect at all.? Maybe that and the ALC problem are related?? The sidetone volume is still very low, haven't looked into that yet.

This is a puzzler. Check with a frequency counter or spectrum analyzer to see if your power is coming out where it is supposed to be. If it is, you may have a band switch, low pass filter, or T/R relay issue. ALC is derived from the wattmeter circuit so you should see something on the meter if you have power. Don't overlook the pushbuttons. Schadow switches are known to become cranky if not used for a long time.

Messed with the PS7 a bit, it seems to be working fine with 13.6 volts measured inside it.? But when I plug in the Jones connector and turn on the rig the fans on the rig and PS come on (they are the original AC fans) but the rig doesn't power up.

The DC power connection is shown on the parent board schematic but doesn't make much sense. Not hard to figure out though. Two of the pins are tied together as ground. Of the other two, one supplies hard power to the PA deck and the other powers the rest of the radio through the power switch. There are two sets of contacts on the power switch, one for the 120V mains and the other for the 13.6 DC.

In good news the filter board is filled with the standard 2.3 filter, 1.8 SSB filter, 6.0 AM filter and 300 Hz CW filter!? And they all work just fine.

Good filter complement. Very flexible.

--

73

-Jim
NU0C

Got the PS working and it was mostly pilot error.? The previous owner had replaced the Jones connector on the DC cord with Molex connectors for whatever reason and had put PowerPoles on the Jones connector..? And for whatever reason I was thinking he had somwhow added that line so I only had to use the other connector for everything.? I finally actually looked at the photo of the PS in the owners manual I downloaded and realized that BOTH cables had to be connected - DUH!? So I cut off the Molex conectors, replaced them with the orginal Jones connector, plugged both into the rig and guess what - it worked!

So that leaves the very low sidetone volume, no forward/reflected power on the meter and the wonky ALC to fix before I put the rig on the air.? I'm wondering if the ALC pot on the ALC board migt be dirty or bad.? I may try a shot of DeOxit to see if that helps.

Any suggestions are greatly appreciated!

73, Bill NZ0T

On Sat, 10 Feb 2024 06:55:52 -0800
"Bill NZ0T" <nz0tham@...> wrote:

Got the PS working and it was mostly pilot error.? The previous owner had replaced the Jones connector on the DC cord with Molex connectors for whatever reason and had put PowerPoles on the Jones connector..

The devil is in the details... :D

So that leaves the very low sidetone volume, no forward/reflected power on the meter and the wonky ALC to fix before I put the rig on the air.? I'm wondering if the ALC pot on the ALC board migt be dirty or bad.? I may try a shot of DeOxit to see if that helps.

Any suggestions are greatly appreciated!

Again, do not use DeOxit on pots. Use a cleaner that is designed specifically for pots, like Faderlube. Or just clean the entire ALC board with alcohol. Drake liked high impedance circuits and crud accumulation on boards can sometimes throw things off.

--

73

-Jim
NU0C

Jim,

No way I'm going to use regular DeOxit!? I'm planning to devote tomorrow to working on the TR-7 so hopefully I can find the issue.
73, Bill NX0T

After fining the much better PDF copy of the sevice manual in the files here I have a plan to try tomorrow.

1.? Very low sidetone volume:? Check R1152 a 330 ohm on the IF/audio board to see if it's shorted, way out of tolerance or has been replaced with a different vvalue to lower the volume.? Maybe a PO wanted to use his keyer sidetone instead of the rig and with no sidetone adjutment in the rig that is how the PO soved it.
2.? Perform the null adjustment of C1901 on the rear LP assembly before I try adjusting the forward and reflected pots.? Maybe thats way out of adjustement and causing the other adjustments to not work which is affecting the ALC adjustment?? Worth a try.

I'll report back tomorrow.? But now it's time to cheer on my Chiefs!

73, Bill NZ0T

If you plan on doing CW you may want to also take a look at the article here by Floyd K8AC:



73

-Jim
NU0C

On Sun, 11 Feb 2024 11:22:56 -0800
"Bill NZ0T" <nz0tham@...> wrote:

After fining the much better PDF copy of the sevice manual in the files here I have a plan to try tomorrow.

1.? Very low sidetone volume:? Check R1152 a 330 ohm on the IF/audio board to see if it's shorted, way out of tolerance or has been replaced with a different vvalue to lower the volume.? Maybe a PO wanted to use his keyer sidetone instead of the rig and with no sidetone adjutment in the rig that is how the PO soved it.
2.? Perform the null adjustment of C1901 on the rear LP assembly before I try adjusting the forward and reflected pots.? Maybe thats way out of adjustement and causing the other adjustments to not work which is affecting the ALC adjustment?? Worth a try.

I'll report back tomorrow.? But now it's time to cheer on my Chiefs!

73, Bill NZ0T

I am attempying to do the wattmeter null adjustment.? The service manual that I downloded from the files section says to connect a VTVM to the refected power input on the ALC board (see section 2-15).? I have read the description of the ALC board there several times but I can't figure out where that input is.? There is no schematic or photo of the board that I can look at - maybe a page is missing?? Anyone know where that point is on the ALC board?

73, Bill NZ0T

The ALC board is part of the High Pass Filter module. You will find the schematic on page 2-80. The inputs are clearly labeled. ALC photo is page 2-73. There is a very early ALC board that is a little different but I have only heard of one confirmed in the field so I have no data on when the final version was put in production.

73

-Jim
NU0C

On Mon, 12 Feb 2024 07:58:28 -0800
"Bill NZ0T" <nz0tham@...> wrote:

I am attempying to do the wattmeter null adjustment.? The service manual that I downloded from the files section says to connect a VTVM to the refected power input on the ALC board (see section 2-15).? I have read the description of the ALC board there several times but I can't figure out where that input is.? There is no schematic or photo of the board that I can look at - maybe a page is missing?? Anyone know where that point is on the ALC board?

73, Bill NZ0T

--

73

-Jim
NU0C

Hi Jim,
Page 2-80 is a blank "Notes" page in my original Service manual notebook.
Dale W4OP

Look for the High Pass Filter Module schematic, Fig. 2-28. There is a list of illustrations in the front of the SM, page V. Page 2-80 is correct for the 1978 manual that I am looking at. I am aware that different revision manuals may have some slight variations in page numbering. I have no intent of researching that. You have all the information you need to find it.

73,

-Jim
NU0C

On Mon, 12 Feb 2024 09:53:58 -0800
"Dale Parfitt" <PARINC1@...> wrote:

Hi Jim,
Page 2-80 is a blank "Notes" page in my original Service manual notebook.
Dale W4OP