RCA 9TC240 Alignment...The start of my education (I hope!)

[Chris K]

Buttons are good. The partner piece is due Monday!

[Chris K]

...and is out for delivery!

[Chris K]

Originally Posted by Penthode

Excellent. When is the generator due to arrive?

And the markers are highlighted for identification by pressing the center buttons on the marker adjustment controls. Are they intact and latch? The only issue I had with mine was one of the buttons was broken and missing.

You have me a bit concerned with the "latch" reference. Is the button in the center of each marker adjustment knob supposed to lock in some sort of on/off detent? None of the five do. There's very little travel on the center buttons and no discernable click or an indication something is being turned on and off.

[Chris K]

OK the 8601 is here It powers up. I think I might need a few more BNC cables! I tried to configure the instruments for the sweep characteristics test and after 5 hook-ups, I ran out!

[Penthode]

Originally Posted by Chris K

You have me a bit concerned with the "latch" reference. Is the button in the center of each marker adjustment knob supposed to lock in some sort of on/off detent? None of the five do. There's very little travel on the center buttons and no discernable click or an indication something is being turned on and off.

The five marker controls on the HP8600a have center selector buttons. When you press the button it latches. Pressing any other the others release it and selects the other. It is a one out of five latch and is purely mechanical.

[Penthode]

Originally Posted by Chris K

OK the 8601 is here It powers up. I think I might need a few more BNC cables! I tried to configure the instruments for the sweep characteristics test and after 4 hook-ups, I ran out!

I count four interconnection hookup cables

Blanking
Sweep
Sweep Inhibit
Aux out of the Sweeper tthe counter in rear.

In addition you need the generator RF out to apply to the circuit under test and a cable, typically scope probe to it's vertical input.

Have you verified that the HP8601a produces a CW output which frequency can be measured on the HP8600a?

Refer to the Operator check on pages 21 and 22 of the BAMA HP8601a manual pdf.

[Chris K]

Originally Posted by Penthode

The five marker controls on the HP8600a have center sector buttons. when you press the button it latches. Pressing any other the others release it and selects the other. It is a one out of five latch and is purely mechanical.

Doesn’t do that. I’ll have to get inside of it. If it’s a mechanical system I should be able to fix it.

[Chris K]

Originally Posted by Penthode

I count four interconnection hookup cables

Blanking
Sweep
Sweep Inhibit
Aux out of the Sweeper tthe counter in rear.

In addition you need the geberator RF out to apply to the circuit under test and a cable, typically scope probe to it's vertical input.

Have you verified that the HP8601a produces a CW output which frequency can be measured on the HP8600a?

Refer to the Operator check on pages 21 and 22 of the BAMA HP8601a manual pdf.

Probably Wednesday night before I can work on the repair to the 8600 and do the testing on the 8601. Work tomorrow and family responsibilities but I’ll be asking for questions in the interim! Thanks so much for your help and time. Means a lot.

[Chris K]

Originally Posted by Penthode

I count four interconnection hookup cables

Blanking
Sweep
Sweep Inhibit
Aux out of the Sweeper tthe counter in rear.

In addition you need the geberator RF out to apply to the circuit under test and a cable, typically scope probe to it's vertical input.

Have you verified that the HP8601a produces a CW output which frequency can be measured on the HP8600a?

Refer to the Operator check on pages 21 and 22 of the BAMA HP8601a manual pdf.

So I have a few questions about this. Some of them will sound like I have no idea what I am doing and in several cases, that's absolutely true! I would like to start with the operator checks on the pages you specified.

Regarding the test setup below...



The connections shown are the only connections needed for this part of the evaluation? Blanking and sweep etc between the 8600 and the 8601 on the rear of both instruments do not need to be connected correct?

What does CW mean? Center wavelength?

RF Detector? What do I use for this? In an analysis setup, it would be the device under test but shouldn't there be a standard for it in a check setup?

For the scope inputs, the sweep output goes to the horizontal (X) input and the output of the RF Detector (whatever that is!) goes to the "Y" input? My scope needs to be in X-Y mode correct?

There...I've put my ignorance out there for all to see! Sometimes, the terms you guys throw around go right over my head! More idiotic questions to come!

[Electronic M]

CW means continuous (unmodulated) wave it's an ancient ham radio term that predates radio being able to convey audio.

Some alignment procedures require a detector probe, some get away with connecting to the detector in the TV or radio.

[Chris K]

Thanks Tom

[Chris K]

Buttons fixed on the 8600. Stuck tab on the switch rail. Lubricates and working fine now.

[Penthode]

Originally Posted by Chris K

So I have a few questions about this. Some of them will sound like I have no idea what I am doing and in several cases, that's absolutely true! I would like to start with the operator checks on the pages you specified.

Regarding the test setup below...



The connections shown are the only connections needed for this part of the evaluation? Blanking and sweep etc between the 8600 and the 8601 on the rear of both instruments do not need to be connected correct?

What does CW mean? Center wavelength?

RF Detector? What do I use for this? In an analysis setup, it would be the device under test but shouldn't there be a standard for it in a check setup?

For the scope inputs, the sweep output goes to the horizontal (X) input and the output of the RF Detector (whatever that is!) goes to the "Y" input? My scope needs to be in X-Y mode correct?

There...I've put my ignorance out there for all to see! Sometimes, the terms you guys throw around go right over my head! More idiotic questions to come!

Yes that is correct on both counts. we want to verify the thing is working.

The blanking and sweep inhibit are to display the markers on the scope. Instead of creating a beat blip marker where you combine the marker generator with the sweep signal at the input or output, this system introduces a marker by momentarily halting the sweep at the frequency point to make it appear brighter.

For the RF detector, I used a simple diode capacitor resistor network like the one attached. The diode i used was the ubiquitous 1N4148. It essentially rectifies and filters to remove the RF carrier and rf envelope to register on the scope. Try bypassing it and providing the y input of the scope has sufficient bandwidth (eg a 100MHz scope) bypassing it you will see the rf carrier sweep.

I have attached the use of this equipment to obtain my IF response with markers which went through the RF detector of the television set as yours will and a sweep of the luma reponse of the set minus an RF detector. This will demonstrate the presence and absence of the RF detector.

[Penthode]

Originally Posted by Chris K

Buttons fixed on the 8600. Stuck tab on the switch rail. Lubricates and working fine now.

Excellent! One of the results of getting old.

[Chris K]

Originally Posted by Penthode

Yes that is correct on both counts. we want to verify the thing is working.

The blanking and sweep inhibit are to display the markers on the scope. Instead of creating a beat blip marker where you combine the marker generator with the sweep signal at the input or output, this system introduces a marker by momentarily halting the sweep at the frequency point to make it appear brighter.

For the RF detector, I used a simple diode capacitor resistor network like the one attached. The diode i used was the ubiquitous 1N4148. It essentially rectifies and filters to remove the RF carrier and rf envelope to register on the scope. Try bypassing it and providing the y input of the scope has sufficient bandwidth (eg a 100MHz scope) bypassing it you will see the rf carrier sweep.

I'll make the detector. Thank you for the design! There may be issues with the 8601. I don't think I'm getting RF output. Output level doesn't change. I'll need to break into it and see what's going on!