Any experience with these?

Discussion in 'Tuners' started by Watthour, Jun 25, 2018.

  1. Watthour

    Watthour Electron Rancher - JS3600

     

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  2. Punker X

    Punker X Moderator Moderator Subscriber

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    180Khz would be considered narrow, my experience this is about there you start to loose fidelity, with increased distortion and separation. Usable, but depending on where you put it may not be the best choice. Notice the obsolete notice. That way with all three pin filters. Options are going to get fewer.
     
  3. Watthour

    Watthour Electron Rancher - JS3600

    Thank you for the reply. I noticed the limited availability when searching for replacements. It's getting to the point of trying to find new 6U5 tubes.

    I knew the IF bandwidth could be an issue, which is why I asked the question. I couldn't find specs on the original application, but noticed that the nulling of signal was less than 2dB at ± 100KHz on the unobtanium G type and right at 3dB on this H type.
     
  4. rcs16

    rcs16 Super Member

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    Funny that I bought some recently as well, as Mike says leaded CF's are all about obsolete, get them while you can.
    I am thinking of getting some of these as well,
    81-SFELF10M7GA00-B0
    They are better suited for a older tuners with a single IF filter path.
     
  5. Watthour

    Watthour Electron Rancher - JS3600

    As far as getting them while I can, I did get a small handful, just in case. I couldn't initially find the G type anywhere but SE Asia. I've now found a source, but stock is low.
     
  6. Punker X

    Punker X Moderator Moderator Subscriber

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    Stocking is getting low and it really takes buying hundreds if not thousands of them to get get matched sets. I always bought my matched filters from Bill Ammons, his stock are getting low also. I just never made investment in getting the filters, time is limited, so just got them from Bill. He says there are SMD mount filters. Hopefully in the future someone will come up with an adapter.
     

     

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  7. rcs16

    rcs16 Super Member

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    Getting those low GDT types such as "MX" are near impossible, except for Bill Ammons, as you say. Folks on fmtuners say that he does not respond to email requests anymore?
    I am today getting a broken Yamaha RX-900/U, it uses many of the special parts used in a T-85 that I have, so getting some spare parts for fixing some Yam. tuners.

    I was actually thinking about making an SMT CF to TH adapter, not a whole lot to it, just time as you say. Give me your input and I'll look into it. A winter project.
     
  8. Punker X

    Punker X Moderator Moderator Subscriber

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    I got a hold of Bill, it just took a while for him to reply. I believe his stocks of matched filters are pretty much depleted. What he does have some were pretty far off from ideal 10.70Mhz.

    I have virtually no experience with the SMT CF's and I imagine it would be even more tedious trying to match them. Are they as good or better than what they would be replacing? Better insertion loss? Lower distortion? Is it worth the effort?
     
  9. rcs16

    rcs16 Super Member

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    I do not have any experience with the smt versions either. It seems to me Murata have scaled down many of the original parts to settle on a few smt types. It amazes me that they still produce cf's, so someone must be still making radios using them.
    How the smt versions compare to the older TH versions I do not know. Could just wrap a few fine solid wires around that one smt version to test them out. how's your eye sight? :)
     
  10. Punker X

    Punker X Moderator Moderator Subscriber

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    Not as good as it was and getting worse everyday.. part of getting old. Going to have to start using Microscope one of these days.
     
  11. rcs16

    rcs16 Super Member

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    I am fortunate in this case to be myopic, so that helps with the up close fine work. Glasses come off , glasses go back on, it is a chore in itself. I do use the big eye mag/lamp setup and even a jewelers loupe to do fine smt work/inspection however. Having a nice Leica stereo mag, like I once use in the EE labs I worked in, were a treat.
    It seems that SFECF10M7 series are the go to devices these days. They are on 1.28mm centers, doing them by hand would work okay :) Would need a pcb for that package if you want to adapt it to the 3 pin leaded version pin config @ 2.54mm centers
     

     

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  12. Bob@FM

    Bob@FM Active Member

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    Yes, Murata ceramic filters with leads are now officially gone...
    Googled it, ironically tomorrow - June 30, 2018 is the last official day for production. But you had to place your order by March 21,2018.
    https://www.ttiinc.com/content/dam/...Hz-Lead-Type-Ceramic-Filters-PCN-00001087.pdf
     
  13. Bob@FM

    Bob@FM Active Member

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    These 280's are the easiest SM to solder, roughly 7mm x 3 mm package, and the leads are same pinout as the old leaded type
    SFECV10M7FA00-R0
    https://www.mouser.com/ProductDetail/Murata-Electronics/SFECV10M7FA00-R0?qs=sGAEpiMZZMtMMXztyU6kdIFTJJQM3M6Q8oelu8IKNP4=

    edit - I would also add they additionally sell 150's and 110's in this same SM package. I normally use 1 or 2 well selected 150's in the IF filter narrow path. Usually 110's are not worth the trouble, they are usually never even close to 10.70, and being so narrow, they cause huge distortion if off only a little bit. But some DX'ers love them.
     
    Last edited: Jun 29, 2018
  14. Bob@FM

    Bob@FM Active Member

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  15. Watthour

    Watthour Electron Rancher - JS3600

    The SFELF10M7H's I received are working, but it seems that I have some IF amplification problems. Once I get that resolved and get the AF signal up to snuff I can report on bandwidth/performance. In the interim, the G parts are on my list (thanks!).
     
  16. Watthour

    Watthour Electron Rancher - JS3600

    Well, they pass signal. It was a challenge to mount them since they are about 1/8th the size of the originals, and lead spacing wasn't even close. I'd replaced the associated .0012µF caps and the first IF amp stage transistor, too, and tweaked it up for the filters at the third IF stage.

    I'm tired of Sansuis.
     

     

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  17. rcs16

    rcs16 Super Member

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    Thanks Bob, I discovered those at Mouser as well and have added them to my current order.

    Watthour, what Sansui model are you working on?
     
  18. Watthour

    Watthour Electron Rancher - JS3600

    350. The filters and IF amplifiers solved it, along with tweaking up the front end and IF after replacements. The sound seems to have fairly decent range, and as I've seen on other Sansuis of this early SS vintage, there is plenty of low-end and almost annoying highs if the treble is cranked up.
     
  19. Watthour

    Watthour Electron Rancher - JS3600

    Looks a little like this:

    [​IMG]
     
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