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

[Chris K]

So I was thinking about this last night and couldn't sleep! Not exactly what a relaxing hobby should do for you! If I could get your thoughts on this, Bob and Penthode and anyone else who would like to contribute ideas, here is what I'd like to do...

I want to find the optimal method and equipment to do alignments on TVs from this era. I'm a bit tired of purchasing vintage equipment in an effort to do this. It seems to always be compromised by inaccuracy and reliability issues.

I was looking at these network analyzers last night and they run the range from bare bones circuit board setups to ridiculously high priced units. I would be willing to spend several hundred dollars on a modern alignment package and go through the process of aligning the RCA with anyone who would be willing to walk through it with me. I could document the process with photos and post a protocol start to finish here on VK. Maybe it could be helpful to others who have had similar struggles with this. I have a shelf full of vintage test equipment purchased with the intent of aligning these TVs that have led to frustration and getting nowhere.

So the path could look like this...I will purchase whatever is needed to do this in the optimal and simplest way with the desired outcome being a workbench decluttered of useless vintage test equipment replaced by a modern and reliable alignment station I can go to with confidence. Hopefully someone could walk through this with me and in doing so, help the community and perhaps satisfy their own curiosity about the process without the expense of actually buying the equipment.

Please, I welcome everyone's thoughts on this. If you think it's a ridiculous idea or you think I don't have the technical know-how to be your remote pair of eyes and hands please let me know. I want to learn the theory and process.

Thank you, everyone, for all of your advice and comments.

[Alex KL-1]

If you invest in a SW digital radio or a freqmeter, you can calibrate these old horses, and makes the investment cheaper, although with more time spending (alas, is a hobby, after all, but these busy times can call otherwise I know...)

[Chris K]

Originally Posted by Alex KL-1

If you invest in a SW digital radio or a freqmeter, you can calibrate these old horses, and makes the investment cheaper, although with more time spending (alas, is a hobby, after all, but these busy times can call otherwise I know...)

Thank you so much for your thoughts. I'd really like to do this with reliable, accurate modern equipment.

[Penthode]

Originally Posted by bandersen

It is the tracking generator. I think you mean marker generator. Yes, you can loosely couple a second generator to create a marker blip

Great to see you had the Tiny SA. You were highlighting my fear as it only would examine RF spectrum. It is not what I would call a network analyser since it does not have a sweep source that tracks with the spectrum analyser display.

The WinWT4 Spectrum Analyzer RF Signal Generator With Tracking Generator appears to be more appropriate and is cheaper too! It has a tracking generator output which is fed to the device under test, in this case the input to the IF amplifier. The output is applied to the RF input of the Spectrum analyser. Then you use the the software to provide the display of the sweep on a computer. No need for an oscilloscope.

Here is the link again:

https://www.ebay.com/itm/126284122318

[Chris K]

Originally Posted by Penthode

Great to see you had the Tiny SA. You were highlighting my fear as it only would examine RF spectrum. It is not what I would call a network analyser since it does not have a sweep source that tracks with the spectrum analyser display.

The WinWT4 Spectrum Analyzer RF Signal Generator With Tracking Generator appears to be more appropriate and is cheaper too! It has a tracking generator output which is fed to the device under test, in this case the input to the IF amplifier. The output is applied to the RF input of the Spectrum analyser. Then you use the the software to provide the display of the sweep on a computer. No need for an oscilloscope.

Here is the link again:

https://www.ebay.com/itm/126284122318

Yes I looked at these in some detail last night. It's worth a shot, even just as a product review for everyone to comment on. The cheapest option isn't necessarily a requirement as I'd gladly spend up to $400 or so for a good quality instrument. I believe these are manufactured and shipped from China so I imagine QA might be an issue and shipping may take several weeks to get to me. I'll order one and we can use it when it arrives but I'm still open to other suggestions even if they are more expensive options.

[Penthode]

Originally Posted by Chris K

I want to find the optimal method and equipment to do alignments on TVs from this era. I'm a bit tired of purchasing vintage equipment in an effort to do this. It seems to always be compromised by inaccuracy and reliability issues.

I think the best approach is a secondhand HP Network analyser. I see a bunch on ebay from modest priced to the astronomical. The HP test equipment in its day was top notch. My HP8600a/HP8601a is essentially a network analyser requiring a separate oscilloscope. It is good for frquencies from 100kHz to 108MHz and use it to sweep align radio and TV sets. I last used it to aligh an RCA CT100 color set and and RCA AR88D Communications Receiver.

The HP8601a Sweeper Generator seems still easy to come by and remains fairly cheap. Mine which I bought on eBay for $40 had a power supply fault which was easily fixed when I received the unit. It however need the HP8600a to provide the true network analysis function as the two devices work in conjenction with each other.

The markr function in the HP8600a/8601a combo works by halting the sweep momentarily to create a blip marking the frequency. There are five independently adjustable marker blips which makes it ideal to simultaneously mark the three traps plus a coulpe to define the passband. Selecting a specific marker makesit brighter on the sweep display and you have a vernier adjustment with accurate digital readout so that the marker is precise to within a few Hertz at 21.25MHz.

New this eqipment in the 1970's was about $8,000 for the pair and I bought them at the time about twenty years ago for about $80 because they provided the best and cheapest solution for my vintage radio TV needs. I higly recommend them for this sort5 of work.

https://xdevs.com/doc/HP_Agilent_Key...0Operating.pdf

https://xdevs.com/doc/HP_Agilent_Keysight/HP8601A.pdf

Here are the HP8600a and HP8601a on ebay. The HP8600a is an earlier version with nixie tubes but otherwise the same. Mine is a bit later using an LED display

https://www.ebay.com/itm/35583162966...Bk9SR9C2oPCoZA

https://www.ebay.com/itm/22625900266...Bk9SR66FvPCoZA

[bandersen]

Originally Posted by Penthode

Great to see you had the Tiny SA. You were highlighting my fear as it only would examine RF spectrum. It is not what I would call a network analyser since it does not have a sweep source that tracks with the spectrum analyser display.

https://www.ebay.com/itm/126284122318

I think you misunderstood. The TinySA is a sweep source. You set the start & stop frequency and sweep rate and it outputs swept RF. Newer versions also output a trigger pulse to sync your scope.

What it does not have is markers. For that you can use a second RF generator and loosely couple it at the injection point.

I think it is a great option for an accurate, easy to use sweep alignment tool.

My main issue is the small size. If I were using it regularly, I'd opt for the much bigger and more capable tinySA Ultra. I believe it can output two frequencies so it might be possible to sweep one output and use the other for a marker.

https://www.amazon.com/AURSINC-TinyS.../dp/B0BMPSSFTK

(edit)
Took a quick look at the specs. https://tinysa.org/wiki/pmwiki.php?n...calDescription
The second output is for calibration and only does 30, 15, 10, 4, 3, 2 or 1 MHZ

So perhaps use a TinySA Ultra for sweeping and TinySA basic for the marker (or any other RF generator for that matter).

[Chris K]

Originally Posted by Penthode

I think the best approach is a secondhand HP Network analyser. I see a bunch on ebay from modest priced to the astronomical. The HP test equipment in its day was top notch. My HP8600a/HP8601a is essentially a network analyser requiring a separate oscilloscope. It is good for frquencies from 100kHz to 108MHz and use it to sweep align radio and TV sets. I last used it to aligh an RCA CT100 color set and and RCA AR88D Communications Receiver.

The HP8601a Sweeper Generator seems still easy to come by and remains fairly cheap. Mine which I bought on eBay for $40 had a power supply fault which was easily fixed when I received the unit. It however need the HP8600a to provide the true network analysis function as the two devices work in conjenction with each other.

The markr function in the HP8600a/8601a combo works by halting the sweep momentarily to create a blip marking the frequency. There are five independently adjustable marker blips which makes it ideal to simultaneously mark the three traps plus a coulpe to define the passband. Selecting a specific marker makesit brighter on the sweep display and you have a vernier adjustment with accurate digital readout so that the marker is precise to within a few Hertz at 21.25MHz.

New this eqipment in the 1970's was about $8,000 for the pair and I bought them at the time about twenty years ago for about $80 because they provided the best and cheapest solution for my vintage radio TV needs. I higly recommend them for this sort5 of work.

https://xdevs.com/doc/HP_Agilent_Key...0Operating.pdf

https://xdevs.com/doc/HP_Agilent_Keysight/HP8601A.pdf

Here are the HP8600a and HP8601a on ebay. The HP8600a is an earlier version with nixie tubes but otherwise the same. Mine is a bit later using an LED display

https://www.ebay.com/itm/35583162966...Bk9SR9C2oPCoZA

https://www.ebay.com/itm/22625900266...Bk9SR66FvPCoZA

Got both the eBay items, the HP8600a and HP8601a pair.

[Penthode]

Originally Posted by Chris K

Got both the eBay items, the HP8600a and HP8601a pair.

Wow that was fast. I have a lot of experience with these things and will be happy to help you set it up.

There is a fair bit of literature on the web about these devices. I would suggest when you obtain then to set up a test network and confirm operation. Generally there is rarely much wrong with this era HP stuff but it is best to make sure.

[Chris K]

Originally Posted by Penthode

Wow that was fast. I have a lot of experience with these things and will be happy to help you set it up.

There is a fair bit of literature on the web about these devices. I would suggest when you obtain then to set up a test network and confirm operation. Generally there is rarely much wrong with this era HP stuff but it is best to make sure.

Looking forward to it!

[Chris K]

I’m going to start researching these instruments and reading the manuals in preparation for delivery. If this works well, I’ll be able to begin to learn about this process and I’ll be able to clear off some shelves! The Tiny SA I originally ordered came today as well so I’ll be playing with that in the meantime. Should be about a week before these arrive so I’ll probably start a new thread then or continue to post in this one. I’ll keep you updated as to arrival time as I get closer to knowing when they’ll be delivered.

[bandersen]

The TinySA will be useful to check if the HP gear is working properly.

[Chris K]

It’s a cool little piece. I imagine at the least I can use it as an accurate RF source?

[Penthode]

Originally Posted by bandersen

I think you misunderstood. The TinySA is a sweep source. You set the start & stop frequency and sweep rate and it outputs swept RF. Newer versions also output a trigger pulse to sync your scope.

What it does not have is markers. For that you can use a second RF generator and loosely couple it at the injection point.

I think it is a great option for an accurate, easy to use sweep alignment tool.

My main issue is the small size. If I were using it regularly, I'd opt for the much bigger and more capable tinySA Ultra. I believe it can output two frequencies so it might be possible to sweep one output and use the other for a marker.

https://www.amazon.com/AURSINC-TinyS.../dp/B0BMPSSFTK

(edit)
Took a quick look at the specs. https://tinysa.org/wiki/pmwiki.php?n...calDescription
The second output is for calibration and only does 30, 15, 10, 4, 3, 2 or 1 MHZ

So perhaps use a TinySA Ultra for sweeping and TinySA basic for the marker (or any other RF generator for that matter).

I understood. A Network Analyser has a calibrated scale display incorporated so that you do not need markers. The precision of the scale is the limiting factor here and I do not think a separate marker source is the answer. More expensive Network analysers have the precision. The cheaper device I suggested the software client may provide sufficient precision to negate the need for a separate marker.

The HP8600a/HP8601a combo sits in between a more modern and expensive Network Analyser and the older sweep gen/ marker solution but is much more efficient. It's versatility is you can use it as an accurate signal source which can be AM and FM modulated. And than be quickly switched to sweep mode with up to five markers with the flip of a few switches.

I shall purchase a Tiny SA as I would like to explore it.

[Penthode]

Originally Posted by bandersen

I think you misunderstood. The TinySA is a sweep source. You set the start & stop frequency and sweep rate and it outputs swept RF. Newer versions also output a trigger pulse to sync your scope.

What it does not have is markers. For that you can use a second RF generator and loosely couple it at the injection point.

I think it is a great option for an accurate, easy to use sweep alignment tool.

My main issue is the small size. If I were using it regularly, I'd opt for the much bigger and more capable tinySA Ultra. I believe it can output two frequencies so it might be possible to sweep one output and use the other for a marker.

https://www.amazon.com/AURSINC-TinyS.../dp/B0BMPSSFTK

(edit)
Took a quick look at the specs. https://tinysa.org/wiki/pmwiki.php?n...calDescription
The second output is for calibration and only does 30, 15, 10, 4, 3, 2 or 1 MHZ

So perhaps use a TinySA Ultra for sweeping and TinySA basic for the marker (or any other RF generator for that matter).

I understood. A Network Analyser has a calibrated scale display incorporated so that you do not need markers. The precision of the scale is the limiting factor here and I do not think a separate marker source is the answer. More expensive Network analysers have the precision. The cheaper device I suggested the software client may provide sufficient precision to negate the need for a separate marker.

The HP8600a/HP8601a combo sits in between a more modern and expensive Network Analyser and the older sweep gen/ marker solution but is much more efficient. It's versatility is you can use it as an accurate signal source which can be AM and FM modulated. And than be quickly switched to sweep mode with up to five markers with the flip of a few switches.

I shall purchase a Tiny SA as I would like to explore it.