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.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
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
|
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=294816Thanks, Benjamin
|
Hi Glenn,
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
toggle quoted message
Show quoted text
On 5/1/2024 9:54 AM, Glenn Little wrote: Another question is U241.
It is listed as 74S00 or 74S02 depending on serial number range.
Why would this part be changed?
|
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.
|
On Wed, May 1, 2024 at 8:57?AM Clark Foley via groups.io <clarkfoley@...> wrote:
I did not check models but it is in your backyard.
This panned out, thanks! Still passively looking for a K217 for my DSA602.
|
Re: FS: Tektronix 7613 w/Horizontal plug-in in, and vertical plug-in
If you're not in the area you can have it shipped, though if it is shipped, I cannot guarantee it's operation upon arrival. I will do my best to pack it.
|
Re: WTB: Tek 500 Series Cover Latches
Try VintageTek Museum
Dave Wise
toggle quoted message
Show quoted text
On May 1, 2024, at 11:06 AM, Gordon, KJ6IKT <gfsmith@...> wrote:
?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
|
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
|
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: 11302A Enhanced Accuracy problem
I have put this on the back burner for now, thanks again for all the help!
|
I did not check models but it is in your backyard.
|
Hi Kevin,
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
toggle quoted message
Show quoted text
On Tue, Apr 30, 2024 at 07:35 PM, Kevin Bowling wrote:
I am wondering if there is anyone within a day's drive of me in the
Southwest US (Arizona, S. California, Nevada, New Mexico) with some
scope carts. I am looking for at least one each K213 and K217 (or
204, 205) and will pay fairly.
Regards,
Kevin
|
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
|
Prodding with a meter reveals that the fan is powered from a transformer winding
It’s a ROTRON model.. Possibly stalled somehow and burnt out the windings ?
So, looks like I need another 115V fan (I am in the UK)
Sent from Mail ( ) for Windows
|
A long time ago I posted a similar inquiry. One of the replies was that Rubbermaid utility carts work well as 'scope carts. I managed to find a used one locally and used it for years to hold my 575. You might look around to see if there is one of those available locally.
DaveD
KC0WJN
toggle quoted message
Show quoted text
On Apr 30, 2024, at 22:35, Kevin Bowling via groups.io <kevin.bowling@...> wrote:
?I am wondering if there is anyone within a day's drive of me in the
Southwest US (Arizona, S. California, Nevada, New Mexico) with some
scope carts. I am looking for at least one each K213 and K217 (or
204, 205) and will pay fairly.
Regards,
Kevin
|
Hello am in Paris
Have many of the great K212 carts excellent choice.
These easily can be broken down to the base, arm and tray and shipped UPS, Fed Ex Gr etc.
Besides epay, suggest you try
1/ ARRL Ham radio fleas in you area
2/ National labs, AF bases, surplus sales eg Kingman AFB, LANL, Sandia, etc.
3. Surplus dealers near those National labs. Most have ebay stores but will sell to you direct if you can visit.
Bon Chance,
Jon
|
Re: 576 grid step amplifier
My first batch of 10 sold out on eBay. Thank you to anyone/everyone who purchased a unit. I have built another 10 and renewed the listing:
If anyone from this group were to be interested in one, I'd be happy to give a 10% discount. Feel to reach out to me directly as well and we can bypass the eBay fees and sales tax.
-Chris
|
I am wondering if there is anyone within a day's drive of me in the
Southwest US (Arizona, S. California, Nevada, New Mexico) with some
scope carts. I am looking for at least one each K213 and K217 (or
204, 205) and will pay fairly.
Regards,
Kevin
|
Re: Looking for dead external mixers Wm490k
Kicking the can down the street...there ought to be a dead external mixer or two that can be better used than just being used as a paper weight? </beg mode off ;-) >
|
Benjamin Badrakh
Loris Bollina
Jean-Paul
