Fortunately, there are still people who dedicate themselves to these technologies that for many are in complete disuse, but that have great value for those who appreciate them. Right at the beginning, the author makes it clear that it is a hobby, and I am very happy to see that time can be used in a pleasant way when there is a real dedication to a hobby and the willingness to share knowledge. My congratulations!
Thanks for the effort. For those of us just starting out, these procedures seem very complicated and it is nice to see how to carry them out. As the owner of a SG165 and SG80 and synthesized HP RF generator, it is helpful to see how they should be used in this application. This will be a go-to video for people in the hobby. Best, Doc
One of the most thorough videos on alignment with the current test equipment available to us hobbyists . I can say for myself that you have helped me with your work here. You should be getting paid for this! Thankyou ever so much.
Great video, Tony! I have struggled in the past getting the discriminator primary coil setting at a point that I felt was 100% correct. I had a 2245 open, and found that the dicriminator circuit is exactly the same as the one on the 2130. I removed the metal cover to the board and connected DMM's to the anode of the positive diode (H503 on the 2245) and to the cathode of the negative diode (H504), and lo and behold, the adjustment to find null point works just like you said! You have removed one of the uncertainties that I had when aligning these tuners. Thanks!
FM transmitter at a radio station I once worked at had two interesting aspects: One of the two major transmitter power tubes was blown, reducing us to quarter power, for which we had to get special FCC dispensation. This caused a lot of frequency drift, since none of the temperatures were where they should be. Also, the built-in feedback system of a heater and internal cooling systems were long since non-functional. We attempted to keep the center frequency right by alternately plugging in a 100W light bulb under the crystal canister, and turning on a fan behind the cabinet. I'm sure we often drifted into the next station's territory more often than not. We'd occasionally get DX reports from concerned folks who were trying to track us. Your analog frequency setting reminded me of this for some reason.
This information is pure gold. Thank you for doing this video. I have a Sencore SG165 and a SG80. I just sold a Sound Technology 1000A ( I never used it) This is the first hands on instruction I have seen. Very clear and simple. I work on Marantz gear as a hobby and have noticed the instructions are not clear or just wrong. Again thanks for the fine instructions.
The chattering mute system needs a SCR (thyristor), that is set to work under its hold current. That way it latches in an instant, and lets go again without the (ususual) need to cut the supply current to the thyristor to unlatch. A small thyristor will have a hold current below a few mA (although it can switch 1/2 A or so), and with that few mA you could drive a transistor that switches the relais. So 1x thyristor, 1x transistor, and the chattering is gone.
Thank you for showing this alignment. I love my 2130 and have really enjoyed learning more about it. By the way Carlos, I do not know what fantastic digital sound you refer to but for over-the-air radio I have yet to hear anything which beats FM. I good tuner is a delight and that is why they are still sought after. Then again, it is nice being ‘almost no one’. Sorry you’re so deeply sad.
Many thanks, Tony, for this video. I've been hoping that you would do a full-blown dive into tuner alignmens. I had a friend give me an ST1000A a couple years ago and my first efforts with it were.....ummm....incomplete. Yeah, lets' call it that! Anyway, you've given me enough courage to dust it off and try again. No worries about it being a long video. I really enjoyed it.
Wow, Tony! Very nice and thorough video with good description of the use of your different signal sources. Nice receiver, but I wonder what they were thinking when they designed that muting circuit..
I remember I attempted to "align" my Kenwood Tuner using its two tuning meters and multi-path output. I also knew where the strongest stations were and where the broadcast originated along with two weaker stations on either end of the dial. The only external equipment I had at the time was a cheap o-scope. I was ABLE to (eventually) get real good alignment..using only a few "reference" stations. The most difficult part was "tweaking" the 19&38khz pilots using an x-y display and a good "stereo" song. I was a teenager at the time and I thought this was a "technical educational" experience that I would NEVER get in school. I never did it again. After I moved away from the NYC area and didn't have as many stations to pick from. Used that Tuner from 1970 to 1999. Not bad.
Tony, I have the Sansui TU-X1 as we have already talked about in email. But I also have the beautiful Marantz Esotec st-8, which is essentially the European+ equivalent version of the 2130 with round scope window, more artistic control knobs, and champagne faceplate. Terrific tuner.
Hi Tony, let me just join the others in saying this was excellent. Especially enjoyed the comparison of equipment. Even choked on my coffee over the 'trick question' about rebuilding the osc board. lol. Count me as one who enjoys long episodes. Thanks again. (..the echo of a distant time comes willowing across the sand. And everything is green and submarine. RIP RW)
Now, how did I miss this one?! I actually have an ST-1000A, and I've actually got it to work as described in its manual, making that weird bowtie shape on the scope and everything. I've aligned my HH Scott 340 receiver with it. It's not very accurate frequency-wise, but I have a decent counter, so that wasn't a problem.
At 1:03.00 re: using two meters. I have had good luck with a single Fluke using the center (zoom) bar graph. Leads shorted, millivolt range zoomed to center, hit the Rel button, then connect and adjust the discriminator to where you can see the graph bouncing around the zero (since the signal there is somewhat noisy on an actual station broadcast). The original 83, 85, III series and 87V all can do this, the center bar graph zoom is a hidden power up feature on the 87V.
Greetings: We may have built this before, but using a 500k or 1 meg trimmer pot (multitude works best) tie the ends together and adjust the wiper for minimum resistance to accurately set the midpoint resistance, glipping the adjustment screw to hold position. Wire the pot ends separately to shortish leads that will connect to the +/- sides of the discriminator circuit. Now measure for minimum DC level between the wiper and gnd (or equal). (Save this balance setting pot for future similar adjustments. HTH.
Thanks, I watched end to end, and learned a lot. As for making tube vids, I think using a camera stand is really important, and maybe also turning off the cell phone ;-)
This is great Tony. I was able to pick up an SG-165 and run it through an HP 3642A. Have you performed the sweep that Marantz mention in many of their tuner alignments? Also what is your connection from generator to receiver? I’ve been using a typical balun transformer but perhaps there are impedance issues. Thanks
I did a whole bunch of signal generator videos. I'm pretty sure some of my earlier videos showed me using the LSG-231. Maybe one day, I'll dig it back out and use it in another video. ;)
Tony. When I referred to stagger-tuning in the previous video, I was talking about AM IF alignment. I've heard the results of a properly stagger-tuned radio, and the results are amazing. I guess most just peak them up and leave it at that. No wonder AM radio gets a bad rap! I know this tuner has a whole IF strip dedicated to the 'WIDE' setting. I'm curious who that's tuned.
The instructions can be unclear on this. I may have to mention it in a follow-up. This tuner has two bandwidth paths and two discriminators. When WIDE band is selected, the signal goes through the first IF strip with the wide SAW filter and then straight into the discriminator (adjusted by L205 & L206). When NARROW band is selected, the signal is rerouted through the narrow IF strip (L202 & L203 adjustments) and an additional SAW filter. It then goes to the same discriminator. The second discriminator is used for driving the scope circuit. If properly aligned, the scope is very accurate for tuning center and multipath display. I took me a while to figure out what was going on, but it's a really neat circuit! Thanks for the comment!
In my experience, a DMM/VTVM, 100 MHz scope, ordinary electronics tools, an isolation transformer, and a good, working CPU (i.e. brain), will work for 99.999% of all diagnostic/troubleshooting/alignment needs. It’s the other 0.001% that costs the big $$$ in specialized test equipment! 😉 Of course, a good schematic always helps! 🤗
1:07:44 - The Keithley 2015 DMM datasheet sayd "can measure total harmonic distortion (THD) over the complete 20Hz to 20kHz audio band and can compute THD+Noise and signal-to-noise plus distortion (SINAD)."
Hi Tony~. I am enjoying all your videos in South Korea. Well recently I got an analog tuner (pioneer TX 710) but its FM frequency is for Japan so that I can not listen Korean FM which is same as US FM frequency (88-108). Have you ever rechanneled Japanese frequency (76-90) to US frequency (88-108)? If so, could you make the video and upload it to show how to rechannel it? Thx Tony~
Hi Tony, Could you use a T connector to leave the counter connected? Also, could you use the scope frequency measurement instead of the counter? Excellent video! Thank you. Cheers Mark
I've quirks on more than one piece of Marantz gear where the screenprint on the circuit boards was wrong. Especially with capacitor polarities. Schematics can also be an issue with Marantz. Excellent gear though.
Another great video. I noticed what looks like a DC-Block on your Frequency counter. I assume this is for protection, which I think I have heard you mention. What frequency range would you recommend for the DC Block for stereo work?
I wish i had Access to all these equipment . Now how can one do it cheaply with diy kits . Get fm signal generator and frequency counter as diy kit ? Its hard to get any of these kit in Europe. Prices are crazy for hobby.
Hey Tony, funny how your video's come up just when I need them... :-) Doing an alignment on a vintage Zenith stereo receiver mid 60's early transistor model. 2nd IF amp failed and after replacement now generating FM clicking. Would love to have the equipment you do (that's another question, ie., how in the world did you come up with all that glorious equipment???) but I digress. In this video you made mention of SpecAn's not being used in the early days due to their expense. These days with just about every digital scope having SpecAn capability via FFT, do you think these complex alignments could be done more simply and cost effectively using them? If so maybe that would make a good video. Keep cranking'em out bro. Yours are really some of the best video's on the tube.
Most of the less expensive scopes do not have the sensitivity, frequency bandwidth or resolution to properly display the FFT of an RF signal. It could possibly be done, but you would need the proper probe and possibly a wide band amplifier module to get the signal level up to where the scope could "see" it.
@@xraytonyb Oh the possibilities... I think I see some fun around the corner (more likely frustration). Keep up the good work! Hope you and yours have a happy Thanksgiving.
Good video. Can someone recommend a good book that explains the theory and process? I found this one "heory and Servicing of Amplitude Modulation, Frequency Modulation and Frequency Modulation Stereo Receivers" but at over $100 for a used, marked up book seems a bit much.
Tony, what piece of equipment would provide only FM MPX modulation that can feed into an RF SG like your HP8647? Are there better/cheaper solutions other than using full featured FM Stereo SG's like the SG-165 just as modulators?
The Marantz instruction to adjust the 76KHz with a pilot signal doesn't make any sense whatsoever. The oscillator will lock onto the pilot and be exactly 4 times its frequency, so there will never be anything to adjust. The idea is to get the _free-running_ speed of the oscillator as close to 76KHz as possible. That way it has to be pulled least into lock with the pilot when it appears, which means lowest phase shift, which means best separation.
@@xraytonyb so you run and you run to catch up with the sun but it's sinking and racing around to come up behind you again the sun is the same in a relative way but you're older shorter of breath and one day closer to death. I think those have to be some of the most profound lyrics ever written. When I first heard that album as a kid I was sucked in like a black hole...
I feel deeply sad watching you spending 2 hours of time to teach people a kind of technology that is already beated by digital sound.... almost no one use FM nowadays.... not only due to the bandwidth but also due to the fact that transmitting stations are fightng to superate one related the other in volume...they compress the sound and push into the limits.....awfull to listen..... only a few people still listen to FM...so..... waste of time...... my sadness is also connected to the fact i am an audio amplifier designer having supplied Brazil with thousands units and several models and you are the one and only in the internet able to give me inputs about circuit analisys and repair....so..... doing what you do kill my personnal moments of pleasure as FM reception do ot interest me...and i doubt this may be interesting to many people now a days.... i am also a HAM....more than 40 years operating HF band radios....also something killed by cell phone and intenet...if someone start to teach (i can do it) about Radio Frequency, will be wasting precious time with something that is a dead technology.... congratulations to you by your great work...sad to see you love to waste time on this subject... a pitty