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external trigger is the z-axis input in XY mode
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Here is a picture of the settings on my analog scope and the trace. Those blips on the line, I can't move them or put anymore on the line so I don't think they're markers nor do I know if I have this scope setup correctly other than having it in X-Y mode.
https://imagizer.imageshack.com/v2/8...924/jWFRWO.jpg https://imagizer.imageshack.com/v2/8...922/52BE9Q.jpg |
BTW I set the center frequency down to 22.25MHz
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I see the x-y inputs to the scope and you have a trace. To confirm the trace sweep is from the HP8601a: the scope is in x-y mode? If you remove the cable to the Ch1 input the trace descends to a dot?
If so, the display you show looks very much like it includes a marker. What have you selected on the 8600a? The control with the button depressed, if you rotate it does the dot move? Please confirm this before we move on. |
I don't see anything hooked to the "Channel 2 or Y" input. (?)
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The HP8600a/8601a combo displays markers by briefly interrupting the sweep to produce a bright spot. Chris's scope is displaying that but he doubts it is the marker spot. I would like to prove that it is. The marker frequency is read from the display of the HP8600a. The whole idea was to be better than beating the a separate RF spot frequency marker with the RF sweep to create a marker blip on the trace. It is supposed to minimize distortion to the swept signal. |
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I SEE IT!! I SEE IT!!
You have Trigger source set to line! Try chan 1 int, the way it is now nay be triggering from the line AC input and overriding the drive you are trying to give it. |
Trigger is not used in XY mode.
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No input = dot roughly in the center of the oscilloscope CH1 connected = line sourced from alignment device And changing the trig source switch (int/line/ext) should have no effect on the dot's movement at all, only input on CH1, if it's working the way it should. info on scope here. https://w140.com/tekwiki/images/1/1c/070-3827-00.pdf page 22 |
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OK,, this just got really confusing then. :scratch2:
If it's all hooked as shown it should be working. https://xdevs.com/doc/HP_Agilent_Key...0Operating.pdf page 11 Given that all cables are OK. Perhaps the marker is set up in an odd way, Pentode may be able to help there, it's clear that the oscilloscope and the 8601A Generator/Sweeper seem to be set correctly. |
I really think there is an issue with the Counter/Marker 8600. Hey, imagine that...I bought a piece of equipment that doesn't work right. How unusual for me.
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All I can say is that it looks as if you are nearly there.
You have ensured the seep is coming from the generator? And the dot you cannot move pressing each and every button? Normally when the button is pressed to select a specific marker, the dot is brighter. I don't think it has been selected from the look of your display. It may be work playing with and cleaning the push button marker switches. |
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When I have the sweeper producing a 3MHz sweep around 50MHz symmetrically, I have the straight line on my scope but...on the display for a marker frequency on the 8600 after say I push the center button, the marker frequency that appears on the frequency display (our favorite Nikki tubes) is not stable. It jumps around very rapidly...too rapid to see so there is no way to select a marker frequency accurately. This is what gives me suspicions it is a hardware issue. |
I wanted to do some basic function tests on the 8600. I've disconnected everything between the 8601 and 8600. I set the 8601 to put out a CW of 20MHz and I connected a cable from the 8601 RF out to the 8600 input jack on the front...at the extreme right. I believe this should make the 8600 a basic frequency counter. I get a real-time reading on the 8600 display that changes as I change the frequency on the 8601. This occurs when I have the scope button pushed in on the 8600. When I press the "CW Counter" button on the front of the 8600, I get a frozen readout of the RF frequency that does not change in real-time when I vary the frequency output of the 8601. If I go back to pressing the scope button, I get the real-time frequency read again.
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Well if you are sure all is hooked up right, and lines are good, but the unit is at fault.
http://bee.mif.pg.gda.pl/ciasteczkow...r/HP/8600A.pdf here is the BIG manual.. :D |
there is a section for "performance tests" in the larger manual that did not seem to be in the smaller one, this may help, and point you in the direction of the fault, if it's not working right.
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Please remake the connections as per the diagram and answer the sweep question. We can then proceed from there step by step. |
That's right...I forgot. It can only count frequencies to a maximum of 15MHz.
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It looks like it is saying for it to display frequency, it has to plot a curve, with a marker at the top, but I could be reading it wrong. but there is a lot of info for set up and testing it in there that has to be followed step by step to get it in the right mode it seems. |
GOOD NEWS!!!!!! and some wtf news
Difficult to see but it is making markers on the horizontal sweep without the RF input!
https://imagizer.imageshack.com/v2/8...924/0O74Xp.jpg The bad news is there was a hardware issue with the 8600. To be honest, after cleaning, switching, spraying etc I did a Shango and picked the front of the instrument up about an inch from the bench and let it bang on the base and viola! The markers appeared. It must be a bad solder joint on one of the boards or a board plug-in not making good contact. Not going to touch it until I get the alignment work setup and then I'll carefully reposition it where it's gonna live. Eventually I'll need to run the issue down. |
That's what My High School Electronics Teacher called a "7th Level Adjustment" take id drop it from about 6-7 inches from the table, and SOMETIMES it works! :D
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Yeah happy it’s working but I wish I knew how! I’m sure that despite very professional packaging something probably got loosened during shipping. Just spent some time rearranging the Enterprise bridge. I hope I don’t burn out the dilithium crystals!
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It looks like I should be having more success than I have...
https://imagizer.imageshack.com/v2/8...923/RTuzUk.jpg |
Excellent news.
I do not know if it is just the photograph but are the nixie elements which are supposed not to light up not being properly extinguished? |
Well...they light up with the frequency when a marker button is pushed in. I may have something goin' on here!
https://imagizer.imageshack.com/v2/8...922/XQsPAF.jpg |
That display looks good to me.
It looks as if you are set up now to do some serious aligning! The thing to remember is that the RCA alignment notes are very complete and accurate. If you cannot get the results expected, it is important to stop and investigate why. Also I always like to support the bell of the CRT with a small pile of books or a wooden frame I would knock together. Letting it dangle, I fear the CRT is always prone to getting damaged. |
Not quite sure about that. I don’t think all is well just yet!
Like Bob, I have the 5” CRT that can be used in place of a 10BP4 installed in the chassis so we’re good there I’m not so sure this setup in the photo is ready for prime time just yet. The trace on the old style analog scope is very diffuse almost like it’s out of focus. It’s nowhere close to being like the alignment trace you posted for your RCA early color TV in terms of quality and sharpness. One of the 2 channels was always a bit disappointing in the crispness of its display trace. So maybe this weekend we can troubleshoot this and see if we can solve the display issues? I purchased a working TEKTRONIX 465B analog scope that has been refurbished and calibrated and guaranteed to work as advertised. If my current, old beat up worn analog is having issues as I suspect it is then we can do this on the newer scope when it arrives |
IDK if this link will work because the item was purchased by me but it looks like a solid performer.
https://www.ebay.com/itm/176481822852 |
What volts/div are you using on the y-axis? Could be you are viewing a very low level signal and there is a lot of noise.
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Did you try increasing the output level of the sweep gen?
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Yes I did...no discernable improvement.
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Input of a 21.25mc 0.1V (and up) RF signal swept symmetrically 1mc into the grid (Pin 1) of the 2nd sound IF and the scope Y input from the junction of C183 and R215. Generator sweep output to the horizontal scope input. Regardless of the fuzzy signal, I was not able to get the Fig. 15 symmetrical positive/negative trace with adjustment of T-113.
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Changing the output level of the sweep gen has no effect on the height of the waveform on the scope? It should have a drastic effect.
Then either the sweep gen isn't working or you have something hooked up wrong. Does the scope display change if you vary the center frequency? Can you see the markers? |
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