Alignment Tools?

Discussion in 'Tuners' started by super98lsc, Oct 7, 2014.

  1. super98lsc

    super98lsc Well-Known Member

    Messages:
    983
    Gadget73
    I am in the procurement process for a generator etc. Looking at the HP 8656B or similar. I had also wondered/searched for PC driven tools, at present I am using my PC with SweepGen for a signal generator. It has served me well for simple testing of amp outputs or x-overs.

    Was hoping the team here could tell me what other tools I would want to add to have a full Alignment tuning suite. (Getting good at it is another story) I have several older Tube RCA consoles and 3 Sansui receivers that all need AM/FM work. And I plan to keep it up as a hobby. Not a shop or reseller. I just really enjoy bringing back vintage gear and surprising friends and todays youth with what the "good stuff" sounded like.

    Tools I have thus far
    • Tektronix 2246 4 Chan Analog Scope
    • Agilent LCR/ESR Meter U1733C with AI
    • Fluke 87 True RMS
    • Fluke 88 True RMS
    • Simpson 260
    • Extech VOM with HFE/Transistor test socket (decent for small transistors)
    • HP Lab Grade DC power supply
    • Variac
    • DBT
     

     

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  2. rcs16

    rcs16 Super Member

    Messages:
    4,165
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    Hi,

    I suggest to go with the 8656B, why for starters, :) I own a working and spares unit.
    The 8640B is a much cleaner SG, as it is cavity tuned, but they are usually more expensive, much harder to fix, older.
    I picked my unit up for IIRC $350, it failed AM mod tests at cal time. I fixed it, it was the MC3410 10-bit DAC. I also have a printed manual from the old days when I worked at the Motorola cal lab.
    Only prob with these older units, certain special parts are scarce and they are difficult to fix, if something breaks. That is why i have a spares unit.
    It is great for tuning up newer tuner units, ones that do not require a IF sweeper.
    Correct, no stereo, RDBS or HD modulation, but that can done with external gear, as suggested. I will try the mentioned PC sound card stereo modulator.

    Good luck
    Rick
     
  3. pustelniakr

    pustelniakr Silver Miner at Large Staff Member Super Mod Moderator Subscriber

    Messages:
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    Location:
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    Leader 3216

    I never needed a user manual. I understand the technology, and the operator controls and feedback are clear and user-intuitive. My unit has been very reliable for a decade of use, and has produced excellent results in calibrating vintage receivers and tuners.

    I was unable to find User or Service manuals from any online source, so I contacted Leader, via their "Contact Us" link in their website. A representative posted an email to me (today) within one hour, with both manuals (pdf form) attached to the email. That is product support and customer service, especially considering that the manuals are of a 1989 vintage.

    Enjoy,
    Rich P
     
  4. ConradH

    ConradH Addicted Member

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    That's great. I've also had customer service way up and beyond the call of duty from Leader. Great company/people.
     
  5. super98lsc

    super98lsc Well-Known Member

    Messages:
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    Last edited: Oct 13, 2014
  6. chazix

    chazix AK Subscriber Subscriber

    Messages:
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    Location:
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    For sure you'll want the manual for the Heathkit. I know amptramp mentioned that manuals were drying up, so here's a pointer to a source that's still online:

    http://www.tauntek.com/heathkit-ig-37.pdf

    Looks like you'll have to improvise something for the RF output connection. It's not like any currently-used standard that I know of. Maybe you can find some sort of pins that fit the connector sockets snugly, and solder them to some 300 ohm twin-lead cable.

    A Tek 2246 doesn't have a frequency counter itself, so I guess I'd say you'd be better off having one than not. You won't need it for the Sansui, though. One thing it would be handy for is making sure the Heathkit's crystal oscillators are still accurate, particularly the 19KHz stereo pilot.

    chazix
     

     

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  7. super98lsc

    super98lsc Well-Known Member

    Messages:
    983
    Chazix,

    Thanks for the link I had only found a schematic but nothing else :).
    • What do you think the odds of the tubes still being good are?
      I found all the tubes available for $65 shipped from TubeDepot.com. I suppose I could wait and test them when it arrives or should I just start with a fresh set?
    • Cant I just change out the RF output to something like a BNC?

    I know my scope has the cursors on it for measuring.. I thought I could output a wave then use the cursors to measure it? It displays the frequency at the top of the screen.
    My FLUKE 87 has a frequency counter in it too which I believe will work for at least the 19Khz Pilot Signal

    The FLUKE- In the Frequency Counter mode, the frequency display
    autoranges to one of five ranges: 199.99 Hz, 1999.9 Hz,
    19.999 kHz, 199.99 kHz, and greater that 200 kHz.
     
    Last edited: Oct 13, 2014
  8. chazix

    chazix AK Subscriber Subscriber

    Messages:
    1,178
    Location:
    Groton MA
    I actually think there's a very good chance the tubes will be good. It's not the sort of gear that I would expect was always powered up. The electrolytics are a different story - you'd probably be best off powering it up through tyour DBT, or maybe your variac if it has a fairly sensitive current meter.

    The choice of cable types for the RF output is not wide open. The output has an impedance of 300 ohms, and unless you're planning to make other modifications, the cable should match. (Run-of-the-mill twin-lead cable is 300 ohm.) How much does this matter in practice? To be honest, probably not much. In particular, you won't do any damage if you use a non-matched cable type.

    I don't really know how the cursor-based frequency measurement on your 'scope works, but it doesn't seem likely that it would be accurate to, say 0.1%. That's the sort of accuracy I would want in many cases - in particular, for stereo pilot frequency. The Fluke is probably a better choice here.

    chazix
     
  9. for_p1

    for_p1 Addicted Member

    Messages:
    5,523
    Location:
    Northern TX
    I looked at one of this things. It is just terrible. You can't expect do any alignment with it. Best use is to simple check if stereo mux is working or not. Distortion level is so high, that you cannot expect doing any alignment better than your receiver already has. Unfortunately there is no work ariund here. If you want align tuner - get real signal generator.
     
  10. KentTeffeteller

    KentTeffeteller Gimpus Stereophilus!

    Messages:
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    Location:
    Athens, TN
    Yes, and you need a good quality one. The Sound Technology is the best made. The late model Sencore and Leader alignment generators are also good choices for most service work on tuners. It must be a low distortion model to even be viable.
     
  11. super98lsc

    super98lsc Well-Known Member

    Messages:
    983
    Guys thanks again for the feedback. Ill have the Vintage Heathkit to display on the wall and look interesting I guess. I also felt iffy about it I found a Leader SG-216 that is in great condition and such... waiting to see if it can be obtained in a decent price range. Sounds like the IG-37 will turn my tuners into Guitar Effects amps.

    If I were to decide to spend $1k on a piece of gear what would guys recommend I target? I dont mind spending money on good tools.
     
    Last edited: Oct 14, 2014

     

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  12. chazix

    chazix AK Subscriber Subscriber

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    A grand should be enough to get you into a Sound Technology.

    At the risk of seeming defensive, my suggestion of the Heathkit was considering both price, and the generation of tuner technology that super98lsc/RM is currently working on. The alignment procedure for a Sansui 5000x calls for an old-school IF sweep, with the discriminator adjusted by eyeball for S curve shape. I'm not convinced that following that procedure would yield significantly better results with a better generator. That's not to say I don't think it's possible to do better, but I think it will require more than just a better generator. For example, I think most would agree that a distortion meter would be needed, and that's another fairly expensive piece of gear that I don't think RM has at the moment.

    Cheers,

    chazix
     
  13. ConradH

    ConradH Addicted Member

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  14. gadget73

    gadget73 junk junkie Subscriber

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    For whatever it may or may not be worth to this discussion, I have checked the audio generator built into my HP 8640b at 0.05% THD, measured on an HP 333a distortion analyzer.
     
  15. rBuckner

    rBuckner Luv 2 Restore Subscriber

    Messages:
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    Location:
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    That's about as low as it can measure so it may be even better! I started out at HP doing production line test on mechanical RF generetors. The 8640 line was right behind me over a short wall and we used to banter back and forth all the time! I can tell you the QC inspectors didn't let an atypical unit go even if it WAS in spec. :yes:
     
  16. super98lsc

    super98lsc Well-Known Member

    Messages:
    983
    I do appreciate all the input. I think the old IG-37 might get this 5000x back in shape for the front end once I finish rebuilding the F-1085 (Tuning Cap and amps inside it). The IF Strip and multiplexer work well. I jumped the tuner from my 2000x over to the IF Strip input of the 5000x and stations were strong 5 and center tuned without issue. So for this particular fix I only need to get the front end squared up once I install the new FET's and resistors and a couple caps that were heat damaged by someone prior to me. I think the guy who "fixed" this unit before selling it to me soldered the tuner with a blowtorch and plumbing solder.

    I have 2 units I am looking at:
    • Leader LSG-216
    • Panasonic VP-7365A
     

     

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  17. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    The Panasonic is a VP-7635A and is a composite signal gen with no RF. It would have to be input to an RF gen with an external audio modulation input. I think the Leader will do. The lower priced one on eBay right now has an issue so avoid that one. The starting price on the other one is very low, make me suspicious it's not so desirable but I didn't research it however.
     
  18. super98lsc

    super98lsc Well-Known Member

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  19. ConradH

    ConradH Addicted Member

    Messages:
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    Location:
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    FM Alignment Generator Distortion Measurements:

    How bad is an SG-165? Well, mine is 2.68% THD @ 357 Hz. It beats the 5% spec, but that's still too lousy to minimize THD on any decent hifi tuner.

    My 8640B does just under 0.045% for both 400 and 1000 hz.

    My Leader LSG-231 comes in at 0.015% @ 1 kHz.

    My Heathkit IG-37 is spec'd at 5% but measures 2-3% on all three frequencies, about the same as the SG-165-see text.

    These are all oscillator outputs, so no idea what the final modulated level is.

    The LSG-231 is a bit rare, but it's tiny, performs well and I use it in combination with the 8640B for all my alignments. It provides a fixed 100 MHz output with control over the modulation. There were at least two different 231 circuits, and the thing that changed was the oscillator. No idea how to tell them apart other than by looking inside at the oscillator circuit. Mine is different than the commonly available schematic and I had to get a matching one from Leader, who had to send to Japan for it.

    I use the SG-165 mostly for sweeping IF strips, for which is does just fine and the built in markers are perfect. It's big!

    I recently got the Heathkit just out of curiosity and other than the high THD, it has a nice collection of features- crystal controlled 19 kHz, IF marker and HF tuning marker harmonics. They're tube units and need some TLC to get working at their best. The ground connections tend to oxidize where the tube socket screws and lugs contact the chassis. With careful attention to those grounds and with good tubes, the THD can be close to 2%. The unit is also full of carbon comp resistors and many will have drifted high and need replacement, along with electrolytic caps. The amplitude bounces a bit with line voltage changes. Not as stable as the SG-165, but a lot smaller on the bench.
     
    Last edited: Dec 17, 2014
    dlucy likes this.
  20. super98lsc

    super98lsc Well-Known Member

    Messages:
    983
    Conrad, I installed that software on my precision workstation just curious it seems to measure a ton of distortion even with no input. Surely it's me or something I'm doing dumb. Any pointers??
     

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