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Re: Translating a post to English
I'd cut and paste the Spanish text into an online Spanish-to-English translator, or, if the text is on a website, as you indicate, use Google translator on that page.
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DaveD KC0WJN On May 2, 2024, at 12:11, spinroyd via groups.io <spinroyd@...> wrote: |
Re: Did I discover a manual error in my SC502?
I see what you mean. In that case, I won't cloud the issue with any more suppositions. I'd be interested in seeing if you find any clarification on it.
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Thanks, Barry - N4BUQ I added more photos. All the other positions match except ch1 |
Re: Did I discover a manual error in my SC502?
If that's the case, then it appears that agrees with CH1. The contacts are listed in 4123 order in the manual so it appears that is the position for CH1.
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Barry - N4BUQ The one in the manual has 4 switch contacts because the first one is the power |
Re: Did I discover a manual error in my SC502?
The one in the manual has 4 switch contacts because the first one is the power contact that is omitted in the mode select section. The first contact appears in the powersupply section. Ignore the 1st contact in the physical image. The last 4 are the ones shown in the manual.
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Re: Did I discover a manual error in my SC502?
The manual shows four switch contacts but the switch in the picture appears to have five. That seems incorrect.
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Thanks, Barry - N4BUQ So my SC502's mode contact switch positions doesn't 100% match the ones in the |
Did I discover a manual error in my SC502?
So my SC502's mode contact switch positions doesn't 100% match the ones in the manual.
Ch1 switch config should be 01100 according to the manual. But for me, the actual switch contact is 01001. Can someone else with an SC502 verify that mine or the manual is correct? Images: /g/TekScopes/albumid=294816 Thanks, Benjamin |
Re: FG503 questions
Hi Glenn,
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As to U241, the internal gates are just used as inverters by tying the inputs together, so NAND or NOR makes no difference here. Each is a drop-in replacement for the other in this case; no PCB layout changes required. I can't think of a good electrical reason to prefer one part to the other in mid-production -- they differ negligibly in prop delay, for example. Perhaps it was just what they could get at the time, or get at a good price, perhaps. -- Tom -- Prof. Thomas H. Lee Allen Ctr., Rm. 205 420 Via Palou Mall Stanford University Stanford, CA 94305-4070 On 5/1/2024 9:54 AM, Glenn Little wrote:
Another question is U241. |
Re: FG503 questions
On Wed, May 1, 2024 at 06:54 PM, Glenn Little wrote:
Hi Glenn, Unfortunately, replacing the "74S..." series logic gates is almost always a lottery win. In circuit design, normally, the 74S series is used due to the higher speed of its logic gates and therefore a very fast step response, you can try with an equivalent code of the 74LS series (low consumption S series), but sometimes they are not fast enough (low consumption means greater slowness), if after replacement you should encounter operating defects or a degradation of the instrument's characteristics, you should search on eBay for a logic gate from the old 74S series. kind regards... Loris IW4AJR -- 73 de IW4AJR Loris |
Re: Tektronix 760 trace issue (it's enormous)
For anyone wondering, it's fixed and the problem was caused by bad resistors in the focus circuit.
R3-R4-R5 were all significantly out of spec. I replaced R1 and R2 while I was there. I added a couple more photos to the album. Thanks for the guidance everyone. |
Re: WTB: Tek 500 Series Cover Latches
Try VintageTek Museum
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Dave Wise On May 1, 2024, at 11:06 AM, Gordon, KJ6IKT <gfsmith@...> wrote: |
WTB: Tek 500 Series Cover Latches
Hi All,
I have an old Tek Model 502 that is missing two of it's cover latches. These are the older latches that have a screw, anti-rotation washer, and plastic flat wingnut. One of them also needs a spacer washer but I can fabricate that. Would anyone have two of these animals out there? Willing to pay shipping and a nominal amount to get them. 73, Gordon KJ6IKT |
FG503 questions
I recently bought a FG503 at a hamfest that was in non working condition.
The serial number of this unit is in the high range. The parts layout agrees with the low range parts layout. The board does not appear to have been changed. Would it be common to have this disagreement with serial numbers? Another question is U241. It is listed as 74S00 or 74S02 depending on serial number range. Why would this part be changed? The sockets are TI and I plan to change them to high quality sockets due to the problems reported with the TI sockets. Any comments about the above before I dive into this unit? Any words of wisdom? Thanks Glenn -- ----------------------------------------------------------------------- Glenn Little ARRL Technical Specialist QCWA LM 28417 Amateur Callsign: WB4UIVwb4uiv@... AMSAT LM 2178 QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR "It is not the class of license that the Amateur holds but the class of the Amateur that holds the license" |
Re: SW US: Carts?
Hi Kevin,
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I would highly recommend that you try Craigslist for Scope carts. They come up fairly regularly and if you have an account with them you can set up alerts. Here is one (though it's not one of your desired models): Gordon On Tue, Apr 30, 2024 at 07:35 PM, Kevin Bowling wrote:
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Re: RM564B non-working fan
It's interesting that the RM564B HAS a fan. My 564B doesn't have a fan, and a check of the 564 manual doesn't show a fan, even though it's full of hollow state heat sources. I guess I should keep in mind that rack mounted devices could not expect the open air ventilation that bench/cart mount scopes could expect. I wonder if Tek automatically added a fan to every rack mount device that had a power dissipation over some threshold.
Is your Rotron fan a 115 VAC fan? If so, It should be easy to find a replacement. -- Jim Adney Madison, WI USA |
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