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
Jim Shorney