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

[Yamamaya42]

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..

[Yamamaya42]

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.

[Penthode]

Originally Posted by Chris K

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.

Unfortunately, the 8600a is not a normal counter. It will not work that way. For it to measure frequency you must reconnect the auxiliary output of the generator. It communicated frequency and the counter input is I believe only able to count lower frequencies.

Please remake the connections as per the diagram and answer the sweep question. We can then proceed from there step by step.

[Chris K]

That's right...I forgot. It can only count frequencies to a maximum of 15MHz.

[Yamamaya42]

Originally Posted by Penthode

Unfortunately, the 8600a is not a normal counter. It will not work that way. For it to measure frequency you must reconnect the auxiliary output of the generator. It communicated frequency and the counter input is I believe only able to count lower frequencies.

Please remake the connections as per the diagram and answer the sweep question. We can then proceed from there step by step.

Been going over the big manual a bit, it's rather convoluted.
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.

[Chris K]

Difficult to see but it is making markers on the horizontal sweep without the RF input!



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.

[Yamamaya42]

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!

[Chris K]

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!

[Chris K]

It looks like I should be having more success than I have...

[Penthode]

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?

[Chris K]

Well...they light up with the frequency when a marker button is pushed in. I may have something goin' on here!

[Penthode]

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.

[Chris K]

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

[Chris K]

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

[bandersen]

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.