In the first half of this video, we repair a Sencore SG-165 stereo Analyzer and Signal Generator. Afterwards, we show 3 different ways to measure frequency when calibrating/aligning a signal generator or radio circuit.
No wasted time there as I just bought one of these and your video gave me a jump start on what to look for when it arrives and how to properly use it. As always, very informative.
Having just purchased a SG165 on Ebay I really enjoyed your video. Sure beats digging it out of the manual and being confused if the SG165 has a problem. Great channel! Thanks
Dude!! I would love if you could do a full video of using the SG165. I don’t quite understand the “terminating in 50 ohm” thing and the subtleties of using the gear. It’s an awesome unit. Would love some in depth demonstration. ☺️🙏🏻
You never waste my time. Excellent info on SG-165. I am using an RCA, WB50 to do old fm radio alignments and I am beginning to make sense of how to do an alignment. So I will keep watching for the great nugets of info that drop here on your channel.
Hello Tony, 1st and foremost thank you very much for sharing your knowledge and expertise to all of us! I would like to ask if you please do a video of aligning a Pioneer SX 50 series tuner using the SG165?
Dear sir, It is an excellent video!! I fixed my Sencore SG-165 but I have problems to use it. I will really appreciate if you could show a video aligning an FM receiver, please. Kindest regards.
Hi. That would be outstanding. I rebuilt mine and everything is spot on on the calibration. And every waveform. But get odd ball result from attempt to sweep align FM. Cant get the waveforms right. Been practicing on a few good amps and still no luck.
I just finished a rebuild on one. Came out great. Made my own probes, did the broken shaft repair which re aligns better if you put screws in the front face of the gang tuning capacitor Sencore leaves out. Calibration spot on and all waveforms exact as in Schematic but cant do FM sweep align to save my life. Do not know why I cannot get the waveforms to show correctly. Been practicing on two Harmon Kardons a 630 with IF cans and a 930 with ceramic filters. Wish i could see you do more with an IF sweep align on the SG165. I'd like to exchange a few notes on waveforms to see if mine is doing same as yours. Maybe in an email?
I've got 2 of these units. The 1st one I got was from an ebay and was missing the power supply. I also built a supply for this unit, but I used a transformer. I do not see one on yours. I also went through every board in the unit and replaced the caps and also replaced all the resistors. All the resistors in my unit were extremely close to falling out of tolerance with the 1%'s being the worst offenders. The 2nd unit works, but I've not done anything with it. Referring to the load resistors, both units I have also show signs of being overloaded. I think that seems to be a common issue.
Or, to be more precise, an oscilloscope shows one the intensity of a signal over time; a signal (spectrum) analyzer shows one intensity of a signal over frequency (which is almost always a logarithmic scale on the vertical axis). It's interesting to note that there are correspondences between the time and frequency domains; a sine wave in one,is a spike (impulse) in the other, and this goes both ways (in theory.)
Good information? I just started working on my 165. Question: I’m going to install phono jacks on the front panel that connect to the meters. Which meter cable pair is for the right meter? Thanks Tony
rub the meter face with a dryer sheet. works well for static reduction and cheaper than the sprays made for the purpose (there's a bunch of other diy solutions the dryer sheet is just the handiest to me.
Hi, great video. Could you give more detail on the power supply board you rebuilt?. I am woking on a SG-165, and the power supply is giving me fits. Thanks for taking the time to make these videos.
Mike, Sorry, I don't have any schematic for the power supply I built in the first one of these I did. I just used a prototype board and made up the power supplies from 7800 and 7900 series voltage regulators. In retrospect, I should have just repaired the original power supply, as building the new one was a pain. You also have to add a circuit for the sweep signal sync. The best bet is to buy the correct replacement components and repair the original power supply board. If you get stumped, you can e-mail me a question at xrtonixaudio@gmail.com. I'll try to help. Also, the service manual that is floating around online has the pages out of order. They are all there, just mixed up.
Thanks, Tony. I'm in the process of gathering everything to rebuild the power supply board. I think I'll keep working that direction as you suggest. I finally noticed the power supply info in the Manual--couldn't find it at first. Thanks for the info.
Great video, makes me want to buy an digital scope. I got an old analog 30MHz scope. You can use a dryer static (Bounce) sheet and rub down the meters to cut down on the static build up.
I just got a sencore sg165 and checked that 75 ohm potentiometer and thought it was bad also. Turns out its 75 ohm between center and one outside terminal and 750 ohm between center and the other outside terminal. I took mine apart and there are multiple carbon traces for the the outside and center conductors to slide on. I cleaned mine with alcohol, put it back together and am going to reinstall it.
Great video Tony. I appreciate your videos. So I have an sg165 and I noticed that it is still generating output signals with the power switched in the off position. The switch is a slide dpdt yet the schematic shows a spst. I was hoping you could shed some light on this.
Great video, I just started a SG-165 restoration project. I know its been awhile ago since you videoed the restoration of the SG-165 depicted in this prestation. I have a quick question if you have time to replay that is. The unit I'm working on has the same issue with R10, 75 ohm L-pad. I happen to have a linear tapped 75 ohm long shaft wire wound pot. You replaced it with a 100 ohm pot with a 2.k something pot. My question or confusion is, my understanding of a L-Pad is that it is basically an adjustable attenuator that maintains constant impedance thru its range. My question is how well did the 100 ohm with a resistor across it work and would a simple pot suffice and not worry myself with the impedance matching?
Good question! An L-Pad has two resistive elements with wipers that move in opposite directions. When properly connected, it forms a type of voltage divider between the input and output. Rotating the control counter-clockwise pulls the output closer to ground while raising the input above ground by an equal amount. This way, the input side will always "see" the same load across it, while the output will have reduced output amplitude (with part of the amplitude being absorbed by the resistor). This allows you to maintain the impedance while lowering the output amplitude. As these circuits were never very accurate to begin with, I really wasn't worried too much about the output impedance. If I was able to replace it with the proper l-pad, I would have, but I just used a pot and I monitor the signal with an external RF voltmeter or spectrum analyzer. In most cases, the exact amplitude isn't important. You most often adjust the output of the SG for a "small/weak" or "strong" signal into the radio. Hope that helps.
@@xraytonyb Thank you for the response! Yeah, I'm just going to proceed with the pot and maybe one day we'll find an actual 75-ohm L-pad. Thanks again for the great videos!
At 9:40 you briefly discuss replacing the 75 ohm L pad with what looks like a single long shaft potentiometer. Are you using a single 100ohm pot, instead of two pots in an L pad?
Hi Tony, I watch your videos all the time and I find them fascinating and very informative. I have a question for you... What type of BNC connectors and cables I should buy to connect my Owon Oscilloscope to my Universal counter and other equipment. I am at a lost for such knowledge. Keep up the good work and thanks for taking the time to share your knowledge.
I have an SG165 with the broken plastic RF Tuning shaft. What is the procedure for replacing the shaft? Looking at it I'm not certain if you need to remove the assembly in the back which contains the bottom row of controls, or if the shaft can be replaced by removing the RF Tuning knob and scale on the front of the unit. I don't want to do any unnecessary disassembly so I thought asking would be the best option before starting.
Great video, I'm trying to calibrate my newly acquired sg-165. You made some comments on impedance of your SA. I believe the SG-165 is 75ohm output and your SA is 50 ohm input. Were you using some type of matching device or did you just not worry about the mismatch for peaking purposes. I have a Rigol 815-TG and would like to use it for this purpose so any info would be helpful. Keep up the great videos, Doc
Great video! I wonder if the Owon scope is like my Rigol: Press the "utility" button, scroll to "counter" and turn on the built in frequency counter. It is more accurate and has better resolution than the standard frequency measurement on the display. Try it? Rob
hey tony! i just picked up one of these in decent shape. the first problem i found was the fuse holder's metal tab was broken off, and there was a 10A fuse in there that was cracked. i checked the service manual for this fuse value, but i couldnt find it on the schematic or the BOM. I dont think it should be 10A tho. do you know the recommended value for this fuse? Thank you for all the awesome content btw :)
thanks for a very goo explanation of your Sencore. Just wondering about your coax test lead I have seen these used by other youtube techs. What sort of cable is it & where's the best place to buy it please?
hi my freind thanks for this video i have a A question can you give me the Specifications of t2 the size and coper wire Diameter in it and the ohm in the legs of it please help if you can you can thanks and god bless you
Hello there! I have a bid on e-bay for this analyser but the problem are if I can use it in Norway as I live here. Our voltage and frequenz are as you know 240V 50Hz. Are there any possebilyti to use this here in Norway? Hope to get an answer. Thank's in advance! Geir Kristiansen Nesna Norway
For the 240 volt mains, you can use a step-up transformer. As for the 50Hz, the SG-165 uses the mains frequency for the sweep generator. I don't know if the adjustment will allow for 50 Hz. It is possible that it might work, but the sweep signal would just be 50Hz instead of 60Hz. I would suggest downloading the service manual and looking at the calibration instructions to see what I'm talking about. Thanks for watching! Tony
Thank's for the answer! I just downloaded the service manual and there it says 50/60Hz but only 110-117Volt. So it should be possible to use it here in Norway with a step-up transformer. That is if I win the bid then. :-)
hi my freind thanks for this video i have a A question can you give me the Specifications of t2 the size and coper wire Diameter in it and the ohm in the legs of it please help if you can you can thanks and god bless you
Great video. I would like to see another or two where you align a couple of different types of receivers using the SG-165.
No wasted time there as I just bought one of these and your video gave me a jump start on what to look for when it arrives and how to properly use it. As always, very informative.
Having just purchased a SG165 on Ebay I really enjoyed your video. Sure beats digging it out of the manual and being confused if the SG165 has a problem. Great channel! Thanks
Great video! I picked up a 165 a year ago and I am ready to check it out and align. Thank you for the useful information!
Dude!! I would love if you could do a full video of using the SG165. I don’t quite understand the “terminating in 50 ohm” thing and the subtleties of using the gear. It’s an awesome unit. Would love some in depth demonstration. ☺️🙏🏻
I did a couple videos on them.
Don’t sell yourself short! You have the gift to teach. I watch Carlson too. I really loved this one. Thanks and keep them coming
You never waste my time. Excellent info on SG-165. I am using an RCA, WB50 to do old fm radio alignments and I am beginning to make sense of how to do an alignment. So I will keep watching for the great nugets of info that drop here on your channel.
I used to have several Sencore when I worked in a repair shop. Never owned a SG-165, nice to see a demo of it.
Brings back memories of my studies in my course with C.I.E. and N.T.S. correspondence training, back in the 60's and 90's.
Hello Tony, 1st and foremost thank you very much for sharing your knowledge and expertise to all of us! I would like to ask if you please do a video of aligning a Pioneer SX 50 series tuner using the SG165?
Kudos, great clip. Totally agree on your appreciation on Chinese test gear. Clean and very professional SG165 repair. Thanks for posting.
Dear sir, It is an excellent video!! I fixed my Sencore SG-165 but I have problems to use it. I will really appreciate if you could show a video aligning an FM receiver, please. Kindest regards.
Hi. That would be outstanding. I rebuilt mine and everything is spot on on the calibration. And every waveform. But get odd ball result from attempt to sweep align FM. Cant get the waveforms right. Been practicing on a few good amps and still no luck.
Very good presentation; one tip, use a bounce sheet and wipe the face of the SG-165 meters, that will reduce or eliminate static buildup.
I just finished a rebuild on one. Came out great. Made my own probes, did the broken shaft repair which re aligns better if you put screws in the front face of the gang tuning capacitor Sencore leaves out. Calibration spot on and all waveforms exact as in Schematic but cant do FM sweep align to save my life. Do not know why I cannot get the waveforms to show correctly. Been practicing on two Harmon Kardons a 630 with IF cans and a 930 with ceramic filters. Wish i could see you do more with an IF sweep align on the SG165. I'd like to exchange a few notes on waveforms to see if mine is doing same as yours. Maybe in an email?
Thanks Tony. Good stuff. I always learn something.
I have one of these too Tony. I used it one time on a AM radio. Once again valuable info here.
I've got 2 of these units. The 1st one I got was from an ebay and was missing the power supply. I also built a supply for this unit, but I used a transformer. I do not see one on yours.
I also went through every board in the unit and replaced the caps and also replaced all the resistors. All the resistors in my unit were extremely close to falling out of tolerance with the 1%'s being the worst offenders.
The 2nd unit works, but I've not done anything with it.
Referring to the load resistors, both units I have also show signs of being overloaded. I think that seems to be a common issue.
Or, to be more precise, an oscilloscope shows one the intensity of a signal over time; a signal (spectrum) analyzer shows one intensity of a signal over frequency (which is almost always a logarithmic scale on the vertical axis). It's interesting to note that there are correspondences between the time and frequency domains; a sine wave in one,is a spike (impulse) in the other, and this goes both ways (in theory.)
Good information? I just started working on my 165. Question: I’m going to install phono jacks on the front panel
that connect to the meters. Which meter cable pair is for the right meter? Thanks Tony
rub the meter face with a dryer sheet. works well for static reduction and cheaper than the sprays made for the purpose (there's a bunch of other diy solutions the dryer sheet is just the handiest to me.
Thanks!
I used to use one of these in a shop in the early 80's.
Hi, great video. Could you give more detail on the power supply board you rebuilt?. I am woking on a SG-165, and the power supply is giving me fits. Thanks for taking the time to make these videos.
Mike,
Sorry, I don't have any schematic for the power supply I built in the first one of these I did. I just used a prototype board and made up the power supplies from 7800 and 7900 series voltage regulators. In retrospect, I should have just repaired the original power supply, as building the new one was a pain. You also have to add a circuit for the sweep signal sync. The best bet is to buy the correct replacement components and repair the original power supply board. If you get stumped, you can e-mail me a question at xrtonixaudio@gmail.com. I'll try to help. Also, the service manual that is floating around online has the pages out of order. They are all there, just mixed up.
Thanks, Tony. I'm in the process of gathering everything to rebuild the power supply board. I think I'll keep working that direction as you suggest. I finally noticed the power supply info in the Manual--couldn't find it at first. Thanks for the info.
Great video, makes me want to buy an digital scope. I got an old analog 30MHz scope.
You can use a dryer static (Bounce) sheet and rub down the meters to cut down on the static build up.
I just got a sencore sg165 and checked that 75 ohm potentiometer and thought it was bad also. Turns out its 75 ohm between center and one outside terminal and 750 ohm between center and the other outside terminal. I took mine apart and there are multiple carbon traces for the the outside and center conductors to slide on. I cleaned mine with alcohol, put it back together and am going to reinstall it.
Great video Tony. I appreciate your videos. So I have an sg165 and I noticed that it is still generating output signals with the power switched in the off position. The switch is a slide dpdt yet the schematic shows a spst. I was hoping you could shed some light on this.
Great video, I just started a SG-165 restoration project. I know its been awhile ago since you videoed the restoration of the SG-165 depicted in this prestation. I have a quick question if you have time to replay that is. The unit I'm working on has the same issue with R10, 75 ohm L-pad. I happen to have a linear tapped 75 ohm long shaft wire wound pot. You replaced it with a 100 ohm pot with a 2.k something pot. My question or confusion is, my understanding of a L-Pad is that it is basically an adjustable attenuator that maintains constant impedance thru its range. My question is how well did the 100 ohm with a resistor across it work and would a simple pot suffice and not worry myself with the impedance matching?
Good question! An L-Pad has two resistive elements with wipers that move in opposite directions. When properly connected, it forms a type of voltage divider between the input and output. Rotating the control counter-clockwise pulls the output closer to ground while raising the input above ground by an equal amount. This way, the input side will always "see" the same load across it, while the output will have reduced output amplitude (with part of the amplitude being absorbed by the resistor). This allows you to maintain the impedance while lowering the output amplitude. As these circuits were never very accurate to begin with, I really wasn't worried too much about the output impedance. If I was able to replace it with the proper l-pad, I would have, but I just used a pot and I monitor the signal with an external RF voltmeter or spectrum analyzer. In most cases, the exact amplitude isn't important. You most often adjust the output of the SG for a "small/weak" or "strong" signal into the radio. Hope that helps.
@@xraytonyb Thank you for the response! Yeah, I'm just going to proceed with the pot and maybe one day we'll find an actual 75-ohm L-pad. Thanks again for the great videos!
At 9:40 you briefly discuss replacing the 75 ohm L pad with what looks like a single long shaft potentiometer. Are you using a single 100ohm pot, instead of two pots in an L pad?
Hi Tony, I watch your videos all the time and I find them fascinating and very informative. I have a question for you... What type of BNC connectors and cables I should buy to connect my Owon Oscilloscope to my Universal counter and other equipment. I am at a lost for such knowledge. Keep up the good work and thanks for taking the time to share your knowledge.
I have an SG165 with the broken plastic RF Tuning shaft. What is the procedure for replacing the shaft? Looking at it I'm not certain if you need to remove the assembly in the back which contains the bottom row of controls, or if the shaft can be replaced by removing the RF Tuning knob and scale on the front of the unit. I don't want to do any unnecessary disassembly so I thought asking would be the best option before starting.
Keep a dryer softener sheet handy for that unruly meter
Timely video. And a good one. I literally opened my SG165 for some TLC. Do you do the alignment with all the shielding installed?
I would like to buy one of this frequency meter , vintage electronic like this are worth to have
Great video, I'm trying to calibrate my newly acquired sg-165. You made some comments on impedance of your SA. I believe the SG-165 is 75ohm output and your SA is 50 ohm input. Were you using some type of matching device or did you just not worry about the mismatch for peaking purposes. I have a Rigol 815-TG and would like to use it for this purpose so any info would be helpful. Keep up the great videos, Doc
Great video! I wonder if the Owon scope is like my Rigol: Press the "utility" button, scroll to "counter" and turn on the built in frequency counter. It is more accurate and has better resolution than the standard frequency measurement on the display. Try it?
Rob
hey tony! i just picked up one of these in decent shape. the first problem i found was the fuse holder's metal tab was broken off, and there was a 10A fuse in there that was cracked. i checked the service manual for this fuse value, but i couldnt find it on the schematic or the BOM. I dont think it should be 10A tho. do you know the recommended value for this fuse?
Thank you for all the awesome content btw :)
thanks for a very goo explanation of your Sencore. Just wondering about your coax test lead I have seen these used by other youtube techs. What sort of cable is it & where's the best place to buy it please?
I cannot see the FM IF output on my scope or frequency counter , does this require an active probe ? Or should I try troubleshooting ?
Sorry meant FM RF 😆
I’m guessing I’m using a scope with too low a bandwidth, and my counter false locks on harmonics ?
hi my freind thanks for this video i have a A question can you give me the Specifications of t2 the size and coper wire Diameter in it and the ohm in the legs of it please help if you can you can thanks and god bless you
hi my freind thanks for this video i have a A question can you give me the Specifications
It’s wipe that meter face with a damp cloth to get rid of the static charge.
Hello there!
I have a bid on e-bay for this analyser but the problem are if I can use it in Norway as I live here. Our voltage and frequenz are as you know 240V 50Hz. Are there any possebilyti to use this here in Norway? Hope to get an answer. Thank's in advance!
Geir Kristiansen
Nesna
Norway
For the 240 volt mains, you can use a step-up transformer. As for the 50Hz, the SG-165 uses the mains frequency for the sweep generator. I don't know if the adjustment will allow for 50 Hz. It is possible that it might work, but the sweep signal would just be 50Hz instead of 60Hz. I would suggest downloading the service manual and looking at the calibration instructions to see what I'm talking about.
Thanks for watching!
Tony
Thank's for the answer! I just downloaded the service manual and there it says 50/60Hz but only 110-117Volt. So it should be possible to use it here in Norway with a step-up transformer.
That is if I win the bid then. :-)
hi
You really have no idea what you are doing if you need this piece of equipment. A power supply board is merely a door bell circuit. Hobbyist!
hi my freind thanks for this video i have a A question can you give me the Specifications of t2 the size and coper wire Diameter in it and the ohm in the legs of it please help if you can you can thanks and god bless you