Ok. Let’s try this again…RCA 9TC240 Alignment
 

After a couple weeks of false starts, equipment changes, troubleshooting and almost throwing several hundred dollars in vintage test equipment across the room I finally have, hopefully, a working combo of the three essentials to do this. A working trio of HP equipment: HP 8600 marker/HP 8601 sweeper generator and an HP oscilloscope rated at 100MHZ

If my friends who tried to help me with this before would like to hop back on board, maybe we can have a do over and try to see if I can follow discussions, theory and perform the hands on tasks resulting in finally…FINALLY seeing some alignment trace shapes on my scope. I’ll be working on the bench tomorrow after 1pm eastern daylight time setting some preliminary checks up. I appreciate all the input, time, knowledge and brainstorming provided in the previous thread. Thanks all!
Chris

So you have the working pair on hand? That is terrific.

Once the equipment is confirmed working and the interconnection cabling is in place, the use of the HP equipment will follow the published alignment documentation. The RCA split sound receiver alignments always begins with the sound IF and Sound discriminator alignment because the proper Video IF alignment is dependent upon the sound aligned first.

I confirmed frequency adjustments work but after moving on and trying the setup for the sweep characteristics setup, I'm getting nonsense on my scope. I think, the issue is my lack of knowledge on this HP 64600B oscilloscope. Most of my oscilloscope use is limited to hooking up a probe in a circuit, pressing "Auto" and comparing what my trace looks like as compared to what's in the service manual.

It must be in XY mode. You cannot use the "auto" button. This is where a cheap, basic analog scope is easier to use. You do not need high bandwidth at all.

I have it in XY mode. I can see the markers and move them but I’m not sure what this is supposed to look like. It’s a function confirmation protocol. Anyway, I think if I move straight to production of the sound discriminator wave and the 21.25 symmetrical trace for the sound IF, with help, I’ll probably learn more than I would going through all the tests. I’ve been in contact with the seller and after many email exchanges I’m confident in his statement the sweep generator works accurately.

Can you show some photos? of the Scope setting, the setting on the 8601a generator, the settings on the 8600a marker?

I am particularly curious what yiou have on the display to start so we may guide you in.

The cables and the sweep characteristics test are setup the way it is pictured in the manual on page 4-3. I put together the RF detector as you sketched out. There are two blanking inputs on the back of the marker generator so I plugged it into the one on the bottom...hey, I flipped a coin. They don't specify an RF frequency, only that the range selector be set as shown. At least the trace on the scope looks like a CRT! :banana::banana::banana: The tall, vertical line is the marker at approx. 106MHz on the counter but I don't think this sweep test is supposed to look like this, is it? My scope is set for XY input.

https://imagizer.imageshack.com/v2/1...924/J7X6oP.jpg

https://imagizer.imageshack.com/v2/1...922/GS9KQf.jpg

https://imagizer.imageshack.com/v2/1...923/wyCOtI.jpg

...and I assumed the ground hookups to the RF out and Y scope input on your RF detector schematic is the line on the bottom and the signal goes through the 1000pf cap and the diode etc?

The first thing I see is the sweep is set to full. That is the full bandwidth from 1.0MHz to 110MHz when the range is set to 110. To sweep across the center frequency indicated in the read out. Refer to page 3-2 in the manual.

Nest set the Sym Sweep with to 1.0MHz for aligning the sound IF and discriminator and fully clockwise to to the Video IF alignment.

Set the dial indicator to 21.25MHz to do the sound alignment and about 44MHz to do the Video IF alignment.

I generally use line truggering (lower left). On the 8600a the center button depressed for scope is correct for the sweep alignment. You press the CW when the generator is in CW to generate and measure the frequency of a fixed CW signal.

The scope I cannot see the settings but as Banderson indicated it must be in X-Y mode.

When it is working correctly, with the test detector, you should see a flat line. When you select a marker button, then rotate the control, you should see a bright marker dot move along the line. The marker display will indicate the exact frequency of the marker at that point. I typically set as you see from my CT-100 IF response, to have the 5 markers from left to right across the the response.

Are you inserting the detector circuit?

I switched on my 8601a, 8600a and the scope. I left the RF out to the scope Y input disconnected. The scope is in X-Y mode. The generator is set for a 3MHz sweep width across 50MHz. So it is sweeping from 48.5 MHz to 51.5MHz with 50.0MHz in the middle.

I set the markers across the band being swept with the center button of the marker selected and set to 49.99MHz. You will see it in the middle of the scope display as the brightest marker because the marker button is depressed.

You should see this BEFORE connected the RF.

Also a correction to my earlier instructions: Put the sweep trigger switch (lower left) to FREE. It eliminates the bright dot on the right which I believe is due to the sweep waiting for the next line trigger. Fee run is fine so long as the swwep speed when aligning is not set too high. (we can discuss that later when you get to that step).

Yes it’s in there. For the test of sweep characteristics. I’ll look at your instructions and work on it. It’s Bedtime for Bonzo right now. Talk with u tomorrow!!

I’m putting the HP manual aside and just following your instructions to the letter from now on! I’ll be able to do more on this tomorrow evening and most of the day Tuesday. I’ll be “working from home “ Tuesday!

Questions...

What is sitting on top of your counter? Is that something I need?

How are the cables connected between the sweep/generator and the counter? Forget the scope right now. I have everything disconnected to start from scratch.

So far, all I have hooked up is the cable to the aux out of the 8601

https://imagizer.imageshack.com/v2/1...922/iLhZUS.jpg

On top of the marker are my wideband HP 403B AC Voltmeter and my HP 200D Generator. I used them for various testing. Most recently for audio distortion measurements in conjunctio with and HP 331A Distortion Meter. The 403B was locally $20, the 200D was free and the 331A was $40.

Attached is your photo with the connections.

Nope...have it all set the way you have it...all hooked up correctly and all levels set as pictured. I have a line with no markers and when the counter is on scope and I press the center marker button, I have a frequency readout that's jumping all over the place and no markers on the screen...just the straight horizontal line.

This is fu%$#ng hopeless. Just not gonna happen

Perhaps before throwing in any towels, or hitting it with a Sledgehammer, you could post pics of everything in detail, front and back, and how it's wired up and set and working (not-working), and perhaps someone who has the same type of set up can spot something that's being overlooked.

Thank you for the encouragement. Sometimes I need to walk away from these things for a few days and reboot my brain. Right now I can't even get this setup to put out a countable RF signal much less sweep and insert markers. I can't even reproduce what I posted a couple of days ago where at least, I saw markers albeit on a bizarre sweep trace that looked like a cone . Maybe my scope is messed up or something shorted in the sweeper or the counter. I don't know. Maybe this weekend, my mentors can walk me through this in real time from the most basic to where I can get a symmetrical swept trace with markers. Right now I'm pretty disgusted and a bit demoralized.

Please post picture of the front of your devices and the rear connections.

Regarding markers. Doesn't this use the z-axis on the scope for intensity modulation? Do you have that hooked up?

It does not use Z modulation. What it does is momentatily stops the sweep at the marker point to make it brighter. Notice the sweep inhibit connection.

You have to rotate the marker controls to se them. When they are within range, the selected markers when making the adjustment will cause the marker counter display to change. Try pushing in the buttons and rotating the marker controls.

Just be patient. It will work!

OK...I'll post pictures of everything

Aux out of the 8601 into counter on 8600

https://imagizer.imageshack.com/v2/1...923/FofjCP.jpg

Blanking out of 8601 and into 8600

https://imagizer.imageshack.com/v2/1...924/IoK12U.jpg
https://imagizer.imageshack.com/v2/1...923/8Mdzez.jpg

Sweep Inhibit out of the 8601 into the 8600

https://imagizer.imageshack.com/v2/1...923/7Mw1yh.jpg
https://imagizer.imageshack.com/v2/1...922/YIk4N5.jpg

Sweep out of the 8601 and into the 8600

https://imagizer.imageshack.com/v2/1...924/OIRBpK.jpg
https://imagizer.imageshack.com/v2/1...924/88wFL8.jpg

Sweep out of the 8600 and into horizontal input on scope

https://imagizer.imageshack.com/v2/1...924/MqCfrS.jpg
https://imagizer.imageshack.com/v2/1...922/0xZGKP.jpg

8601 on and set for CW at 50MHz. 8600 showing frequency with the scope button pushed in.

https://imagizer.imageshack.com/v2/1...923/BB0sIT.jpg
https://imagizer.imageshack.com/v2/1...922/eIZndr.jpg

8601 set for a symmetrical 3MHz sweep around 50MHz at 0 dBm. Frequency displayed on 8600 shows a stable frequency read with the center button pushed in but actually the frequency display is almost unreadable as it flashes with jumbled frequencies all over the place. No markers on trace. No amount of turning the marker setting control to left and right extremes changes anything.

https://imagizer.imageshack.com/v2/1...922/sjhNZv.jpg
https://imagizer.imageshack.com/v2/1...922/V7UTf8.jpg
https://imagizer.imageshack.com/v2/1...923/qmLHgZ.jpg
https://imagizer.imageshack.com/v2/1...923/ehRgrE.jpg

I've tried all the other marker buttons with no change. Marker height adjustment on 8600 turned up almost full but there's no change no matter what I do. Scope is in X-Y mode.

He's using a digital scope, so I don't think sweep inhibit is going to work. It's not going to get brighter if the sweep pauses. I think he'll need to use the z-axis option.

Can you take a couple steps back so we can see how you have the cables connected?

I'd also go with a lower frequency than 50MHz. You goal is to align a set with 22MHz IF. The higher the frequency, the more strange effects pop up.

So, this is a case where a cheap analog oscilloscope from evil bay would help, but you can prob get the digital one to work!

I posted photos of all the cable hookups. I do have a Textronix 60MHz analog scope but I don’t know how to set it to X-Y input

it should be quite easy, they all can do it!

My scope is too advanced for this? What the hell?

It's not too advanced. Digital operates in some fundamentally different ways than analog.
The longer the electron beam stays in one spot, the brighter it gets in an analog scope. Digitial does not work this way.

Thats a consequence of mixing gear from different eras.

It's hard to follow all the close up photos and read the descriptions.

It would be helpful is we could see your whole setup in one photos. See the whole cable from end-to-end. That way we can see how it is all hooked up.

What model Tek scope?

I hooked everything up the way Penthode documented in his photo. From sweeper to counter:
Aux out to counter
Inhibit to inhibit
Blanking to blanking
Sweep out to sweep in
Sweep out from 8600 to horizontal scope input

OK, well inhibit isn't going to work with your scope and you have nothing on the vertical so all you will see is a horizontal line. Meaning that, so far, it looks like it should.

I posted sequential photos of hooking up the cables one by one because these cables are 3 feet long and too jumbled up like a plate of noodles to follow from the 8601 to the 8600. But here you go as best I can

https://imagizer.imageshack.com/v2/8...923/iQf3hY.jpg
https://imagizer.imageshack.com/v2/8...922/BXK8Sz.jpg
https://imagizer.imageshack.com/v2/8...922/5QIGgG.jpg
https://imagizer.imageshack.com/v2/8...924/ONpyes.jpg
https://imagizer.imageshack.com/v2/8...923/OykxMm.jpg

But I don't see markers...Penthode showed this setup without a vertical input and he had 5 markers on the horizontal trace. That's what I'm trying to reproduce but there are no markers.

Would a Textronix 465 make all of this easier if I can get my hands on a working one?

you said you had an analog scope, what type is it?

In the latest picture but I haven’t used it in years and one of the beams is messed up

Just any plain old scope with a an X-Y display will work. Is something inhibiting the display? Make sure the scope is not set to trigger.

Without the RF connected you should see a horizintal line trace. The dots will appears when the marker controls are set mid position. Remember if the marker controls are set fully CW or CCW, you will not see the dots. (And CW in this case is Clock Wise!)

Let's look for the sweep line first. What is inhibiting the trace on the scope? If the sweep output of the generator is not reaching the x input of the scope, you should just see a dot in the center of the screen. It may be you have the scope set to deflect the trace off screen to the left or right.

Maybe to start, let us see the scope display with a dot in the center of the display with NOTHING connected. Then connect the sweep x input to the scope. You then need to raise the brightness and/or adjust the scope X channel centering control. Also make sure you start with the highest setting of the v/div control and it would be useful to begin with the X Channel set to AC input.

I can't see any pics here @ work...

will have to wait till later.

Correct. You will NOT see markers using the setup he outlined using a digital scope. You cannot reproduce it using the HP digital scope using the inhibit technique.

I suggest you try connecting the Z-axis output to the z-axis input on the digital scope. If that doesn't work, you will have to use an analog scope.

Yes, a 465 or 2213 will work. Rotate the timebase on the 2213 to XY