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575 - advice sought from owners
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I've just bought (but not yet collected) a 575, I think the 400V option. I suspect it's been stored several years unused. This will be my first piece of Tek valve kit (apart from a 130). Is there an informaiton resource for 575's which gives pointers to particular isues/ problems etc? Am I likely to have any EHT transformer worries? etc. etc.
Many thanks John |
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Ho John,
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Congratulations on getting the 575 400V version (575 Mod 122C). You should search through the archives for advice on bringing up older vacuum tube instruments carefully to allow the electrolytic caps time to reform. That is the most important thing you should do. The HV circuitry is sensitive to moisture so if the 575 was stored in a damp place you will need to dry the HV parts by baking them, This can be done with a small heater in some kind of enclosure that will retain the heat. It does not have to be very hot (100F to 125F) but you should allow at least a week if you think the HV circuits got damp. Finally once you feel ready to turn the 575 on use a Variac and bring the voltage up gradually watching the current draw. If you put a lamp bulb in series it will act as an indicator and prevent the 575 from suddenly drawing too much current. These are some of the tricks of the trade that other members have taught me over the years. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
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Hi John:
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Before you fire your 575 up check that there are fuses in series with pins 14 and 16 (two fuses). I had a short in C244 which did not draw enough current to pop F601. The short overheated power transformer T601 until it shorted internally, it was toast.. I was lucky enough to find a replacement transformer for $125. The service manual states that the fuses were present on serial numbers X8030 and above. If you need to install them on your 575 here is what I did. I removed the two 6-32 screws on the front and interior side of T601 and installed fuse holders using slightly longer screws. Then I wired pins 14 to one and pin 16 to the other one and the original wires going to these pins to the load side of the fuses. I also installed modern electrolytic caps in place of C602, C611A&B, C620, C240, C241, C242, C243, C244, C641, C666A&B using standoff terminals. I left the disconnected chassis mount electrolytic caps in place for aesthetic purposes and put all the axial caps underneath the chassis. I found that the heater of V602 was open so I left the tube in place and wired in two 1N4007 diodes. V642 was OK so I left it alone. I increased the rated voltage on each cap I replaced by at least a factor of 2. Good luck with your new 575. They are a remarkable piece of test equipment and well worth the investment of time and resources to maintain them. Reed Dickinson reed714@... On 6/10/2018 9:04 AM, John wrote:
I've just bought (but not yet collected) a 575, I think the 400V option. I suspect it's been stored several years unused. This will be my first piece of Tek valve kit (apart from a 130). Is there an informaiton resource for 575's which gives pointers to particular isues/ problems etc? Am I likely to have any EHT transformer worries? etc. etc. |
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There are a number of paper capacitors in the HV section. (Amongst other
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locations). I'm sure folks will disagree, but I'd recommend preemptively replacing them. (Any capacitor described as PTM in the parts list is paper.) Be careful with C809, if you decide to replace it, its soldered directly across T801. The wires for the transformer, which will likely come out with the capacitor, are (very) fine. David Obligatory: If anyone wants a non-Mod122C, and is in the Dayton Ohio area, and is willing to pick it up, holler. It has been restored, and was running last I tried it. (No, I will not ship, sorry) On Sun, Jun 10, 2018 at 5:23 PM, John <John@...> wrote:
Thanks for the advice guys: I do normally run stuff up on a variac, and I |
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tom jobe
Hi David,
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What type of capacitors do you suggest replacing the 575 paper caps with, and where do you buy them? Thank you to all that have contributed to this 575 topic! tom jobe... On 6/10/2018 3:17 PM, David Holland wrote:
There are a number of paper capacitors in the HV section. (Amongst other |
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For the PTM caps, in general, I used Mallory 630V polyester film caps
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from from Mouser.. I restuffed the electrolytic cans. I *think* this is the parts list I used when I restored the non-Mod122... If anyone uses it, please double check the parts, I sometimes make last minute substitutions, that may not have made it back into the spreadsheet. (Yes, I shot-gunned all EMC, and PTM capacitors and one cap I thought might of been a Micamold (paper) cap.) Identifier Capacitance Type Voltage Tolerance Part # C102 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C105 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C108 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C122 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C128 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C130 .047uf PTM 400v 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C145 .0015uf Mica (mold) 500v 10.00% 5982-19-500V1500P 1.86 Cornell Dubilier Mica Capacitors MICA 1500pF 500V 5% C186 .022uf PTM 400v 539-150223J630DB 0.54 Mallory Polyester Film Capacitors 630V .022uF 5% C232 .001uf PTM 600v 539-150102K630BB 0.41 Mallory Polyester Film Capacitors 630V .001uF 10% C240 2000uf EMC 20v 661-EKMGG250ELL222MK 1.32 United Chemi-Con Aluminum Electrolytic Capacitors - Leaded 25volts 2200uF 12.5X25 C241 2000uf EMC 20v 661-EKMGG250ELL222MK 1.32 United Chemi-Con Aluminum Electrolytic Capacitors - Leaded 25volts 2200uF 12.5X25 C242 2000uf EMC 20v 661-EKMGG250ELL222MK 1.32 United Chemi-Con Aluminum Electrolytic Capacitors - Leaded 25volts 2200uF 12.5X25 C243 2000uf EMC 20v 661-EKMGG250ELL222MK 1.32 United Chemi-Con Aluminum Electrolytic Capacitors - Leaded 25volts 2200uF 12.5X25 C244 150uf EMC 150v 661-EKXG251ELL151MM2 2.01 United Chemi-Con Aluminum Electrolytic Capacitors - Leaded 250volts 150uF 18X25 C267 .001uf 600v 539-150102K630BB 0.41 Mallory C602 2 x 20uf EMC 450v 647-UVY2W220MHD (20uF) 1.14 Nichicon Aluminum Electrolytic Capacitors - Leaded 450volts 22uF 12.5x25 20% 5LS C611A,B 2 x 20uf EMC 450v 647-UPZ2W390MHD (39uF) 1.48 Nichicon Aluminum Electrolytic Capacitors - Leaded 450volts 39uF 12.5X35.5 20% C613 .01uf PTM 400v 539-150103K630BB 0.48 Mallory Polyester Film Capacitors 630V .01uF 10% C620 125uf EMC 350v 647-UPT2G121MHD 2.05 Nichicon Aluminum Electrolytic Capacitors - Leaded 400volts 120uF 16X40 20% C630 .01uf PTM 400v 539-150103K630BB 0.48 Mallory Polyester Film Capacitors 630V .01uF 10% C641 2 x 20uf EMC 450v 647-UVY2W220MHD 1.14 Nichicon Aluminum Electrolytic Capacitors - Leaded 450volts 22uF 12.5x25 20% 5LS C644 .01uf PTM 400v 539-150103K630BB 0.48 Mallory Polyester Film Capacitors 630V .01uF 10% C655 .01uf PTM 400v 539-150103K630BB 0.48 Mallory Polyester Film Capacitors 630V .01uF 10% C666 2 x 20uf EMC 450v 647-UVY2W220MHD 1.14 Nichicon Aluminum Electrolytic Capacitors - Leaded 450volts 22uF 12.5x25 20% 5LS C802 .001uf PTM 600v 539-150102K630BB 0.41 Mallory Polyester Film Capacitors 630V .001uF 10% C808 .01uf PTM 600v 539-150103K630BB 0.48 Mallory Polyester Film Capacitors 630V .01uF 10% C809 .001uf PTM 600v 539-150102K630BB 0.41 Mallory Polyester Film Capacitors 630V .001uF 10% C811 .047uf PTM 600v 10.00% 539-150473J630EC 0.66 Mallory Polyester Film Capacitors 630V .047uF 5% C816 .022uf PTM 600v 539-150223J630DB 0.54 Mallory Polyester Film Capacitors 630V .022uF 5% David On Sun, Jun 10, 2018 at 6:25 PM, tom jobe <tomjobe@...> wrote:
Hi David, |
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Holy Formatting Failure Batman...... :-(
I uploaded the original spreadsheet here: /g/TekScopes/files/Tektronix%20575%20Parts On Sun, Jun 10, 2018 at 6:43 PM, David Holland <david.w.holland@...> wrote: For the PTM caps, in general, I used Mallory 630V polyester film caps |
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Nah its not so bad. Was only like 25-30$ (american) worth, but it was a
few years ago, so perhaps pricing has changed. But no, the only testing I did on the old paper caps was to throw them in the trash. They made a noise when going in, so I presume they were bad. A few of the electros were definitely dried out tho. I had to take them apart for restuffing. David On Tue, Jun 12, 2018 at 6:18 AM John <John@...> wrote: Thanks David. That's quite a list of capacitors: did you check the paperSent from Mobile Annoyance thingy, please pardon any typos |
John Sykes
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