Pioneer TX 930 Part 3 - FM Stereo and AM alignment
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- čas přidán 21. 04. 2022
- Time to wrap this up! The alternate title for these should be how to turn a $10 tuner into a $20 tuner. :)
HP 8904A- To insure the unit will do FM Stereo modulation it must have Option 1 and be serial number 2948A or above.
Ray -- thank you for your videos! I have learned more about tuning in the past 1 ½ hrs watching than all others. Just getting started in electronics and this explains things in details that were not available other places. Thank you again!
Thanks Brett! Comments like this make my day!
There is a good article on the HP 8904A in the Feburary 1989 issue of the Hewlett-Packard Journal (search for HPJ-1989-02,pdf), on page 74. They show you how to set up FM encoding on the earlier models, using the 4 independent signal generators, one at 39KHz(90 deg), the next at 37KHz(270 deg), one at 19 KHz and the last one at 1 KHz. Jut have to make sure your unit has the 4 independent oscillators (option 1). The later version has the stereo mode built-in.
@ 10:10 7.5 KHz deviation is 10% of 75KHz deviation. So either set the pilot to 7.5KHz **deviation** or 10% **modulation level** .
Ray, Just now getting into radio/alignment, I have the HP 8657 D and it has been difficult to find anyone on how to truly use this equipment in detail. Thank you so much!! I now have more confidence in using my generator. Maybe you can do a video on some of the amplitude settings like dbm,db, uF, . I have seen different settings but they do not explain how or why like you do in this video. Again, thank you!!!!
Thanks for the kind words, Paul! Units of measurement can be confusing. Making matters worse, the Japanese tuners use a different unit of measurement than the US, and the antenna impedance of 75Ω means you have to use some kind of converter, introducing some loss.
You never stop learning when you're into this kind of stuff. Most days I find that exciting, other days it's just daunting!
HP 8904A- To insure the unit will do FM Stereo modulation it must have Option 1 and be serial number 2948A or above.
Ray, nice video as always. I just picked up a 8904A unit. The display is OK, but not super bright. I was wondering where you got a replacement display for the unit? Was it an exact match, or did you have to make some modifications to get it to fit in. Thanks in advance... Robert, San Diego
Ray, Great series! Any suggestions for feeding a composite MPX signal into a AM/FM signal generator that's inexpensive for a newbie/hobbyist. Also, any alternatives to an expensive distortion meter! I want to venture into RF basic tuning but only as a hobby. A video on "tuning for cheap hobbyists" would be great!
Not a bad idea! While sometimes cumbersome, there are computer based solutions for distortion measurement, and even composite multiplex signals. But RF is RF, so I'll have to think about that.
Hi Ray, glad I found your channel. Very informative. Graduated long, long ago as an electronics engineer but got onto a different career path. Hence my knowledge is rusty. Your channel is both a good refresher and an eye opener into areas I am not so familiar with. I took note of your advice regarding FM tuner alignment for an HP8904 to have option 1 installed, but I am not clear as to why you say the serial number must be 2904A or higher. Do you mind explaining?
Don't mind at all. The option for FM stereo modulation was only added at that serial number and higher. Option 1 is multiple outputs.
@@raygianelli3612 Thanks for your swift reply, Ray. I have meanwhile downloaded the "HP 8904A Operation & Calibration Guide" and found that serial number reference you had mentioned. That guide says:"Note: Hop RAM Sequence Mode and FM Stereo Composite Generator functions are only available
in Option 001 instruments with serial prefixes 2948A and above." 👍
Hi Ray, Thanks for the videos! I'm new to FM alignment but learning with your help. For an amateur, would it be better (or possible these days) to look for an AM FM generator with built in stereo modulation capabilities?
Regards, Peter in Canada
Hi Peter. Frankly, it's better for anyone regardless of skill level to have an all in one solution. Panasonic, Leader, Kikosui and Kenwood all made some really nice synthesized generators that had multiplex capabilities. The trick is finding one at a price you can live with. I came across the HP 8657A I use at a great price, then had to find a way to externally modulate it. At the end of the day it's all about what you're willing to spend and how patient you can be, as these things are all out of production at this point.
Another excellent GNLE video! Could you expand on replacing the 8904's display? Where did you purchase that? Thanks!
Hi Wil. I followed the process posted by Roberto Barrios here:
www.rbarrios.com/projects/8904ALCD/
and purchased a display from eBay; any HD44780-compatible 40x2 5 volt display should work:
www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=lcd+40x2+hd44780&_sacat=0&_odkw=lcd+40x2&_osacat=0
@@raygianelli3612 thank you sir!
@@Wil_Bloodworth Let me know how it comes out. Pics really don't capture the huge difference the replacement display makes.
@@raygianelli3612 Well, I don't own one... yet. But my decision to purchase one has been greatly influenced by your usage of it as well as the screen replacement. I've got my eye on a couple right now.
I noticed you seem to be using a scope probe to connect to your frequency counter, is that correct? I have an HP 53132A frequency counter with a 1M ohm option, but I never thought of using a scope probe. That would make connecting much easier. If so, do you suggest using the probe in 1x or 10x.
The probe is convenient, but more importantly adds some isolation between the counter and device under test. You don't want your test equipment affecting the circuit you're testing.
Thank you for the video, Im intrested in the visual analyzer software, several software analyzers that come up when I look for search visual analyzers, could you share the link to the actual software your using? Thanks again for the video!
Hi David. The link is:
www.sillanumsoft.org/
Thanks for the kind words!
Were you just laying the AM antenna on the disconnected Coax for the AM alignment?
No, IIRC this tuner had AM terminals on the back, and I connected to them. If the unit has a loopstick antenna I used a few wraps of wire around it and connected to the generator.
Hi Sir! I hate to pull you into this debate, but I value your knowledge. I'm of the school that says there "may" be a difference in cheap/expensive speaker cable and connectors, but the return on investment is poor at best. I don't have the equipment to prove to guys like Paul ans Danny that their hype is just that... hype. Now, if I had unlimited funds... you bet your butt I'd buy these grossly expensive cables. However, there are so many other parameters along the "entire" signal path that can/will change audio quality. And better areas to focus a limited budget.
What are your thoughts and can you or have you ever tried to prove one cable verse another really could make an audible difference?
In my opinion, it's not the quality of the connector/cable, it's the quality of the install and the confirmation of a secure connection for the signal path.
I won't blame you if you stay out of this arena. Cheers!
While there are many opinions on this subject the simple fact is there's no science to back it up. Wikipedia has a good common sense page on speaker wire, and it states that wire resistance is the largest determining factor. Any any decent copper wire will be fine. For a real fun read do a search on monster cable vs coat hangers.
@@raygianelli3612 Thank you sir!