Date   

Re: TDS3012B to TDS3052B upgrade

Dave Casey
 

It works because the hardware was designed for the 500MHz bandwidth from
the beginning. The firmware limits the bandwidth based on model number.
That said, there is some debate as to whether there was any "binning" of
hardware based on performance (such that scopes which didn't meet spec at
500MHz but did at 300MHz became TDS3032s and 3034s instead of 3052s and
3054s). This doesn't mean that such a scope wouldn't be usable at higher
frequencies if the bandwidth limitation were removed, just that it might
not meet Tek's advertised specs. There's another camp that says they're all
good to the full bandwidth, carte blanche. Either way, your 3012 was
probably not calibrated above 100MHz, so if you do the upgrade you may not
realize the full benefit without a calibration.

Dave Casey

On Sat, Jan 25, 2020 at 9:55 PM Tom B <tbryan@...> wrote:

Hello All,

I have seen a lot of postings from people who have upgraded the
bandwidth of their TDS3000 scopes with firmware. I have a TDS3012B
that I was thinking about doing that with but it seems strange that you
could go from 100MHz to 500MHz without any hardware changes. What I
want to know is; how well does this work? Are there any issues to watch
out for?

Tom Bryan
N3AJA






TDS3012B to TDS3052B upgrade

Tom B
 

Hello All,

I have seen a lot of postings from people who have upgraded the bandwidth of their TDS3000 scopes with firmware.   I have a TDS3012B that I was thinking about doing that with but it seems strange that you could go from 100MHz to 500MHz without any hardware changes.  What I want to know is; how well does this work?  Are there any issues to watch out for?

Tom Bryan
N3AJA


Re: Your generosity is STUNNING!

p mc
 

Jay: you don't get a 'show quoted text' button w/Dennis' mesg?

On Sat, Jan 25, 2020 at 06:18 AM, Jay Walling wrote:


Hi Dave,
Fortunately that day is very far off.
Dennis Tillman W7PF
Say, didn't you just post about putting context in replies? ;^)

Jay


Re: 2465B - Weak Readout Intensity

flanneltuba@...
 

On Fri, Jan 24, 2020 at 01:12 AM, satbeginner wrote:

The 2465x uses what I call a "fly by wire" control system.
...
The sample and hold circuits are build using a simple opamp circuit.
The output of the analog switch charges a capacitor, and the high input
impedance of the opamp keeps it at the presented level.
The opamp shifts the level depending on what the functionality needs.

I have seen these sample capacitors go bad as well as the opamps. (TLO72???)
Thank you for pointing this out! This illuminates an entire section of the DAC "fly by wire" circuit that I have heretofore overlooked.
Certainly before I go to the monumental effort of performing a CRT swap, I will sniff my way carefully thought this MUX'd sample-and-hold circuitry.

I have ordered a CRT, which hopefully will be of the 2465A/B flavor, but I'd be nothing but glad to just put it up on a shelf or resell it instead of having to install it!

Also let me add my "+" to the massively informative, if not exasperatingly long and multilayered EEVBlog "2465B Teardown" thread. I spent hours pouring over that thread—hours well spent for anyone diving into a 2565B restoration. It was that thread that essentially illustrated the finer points of repairing the later model A5 board with its notorious leaky 'lytics.

- Scott


Re: P6201 probe Q100 FET replacement

Gary Appel
 

I think that years ago I got some replacement FETs from Dean Kidd, and they had to be mounted upside down because the lead configuration was reversed.

Gary Appel

On 1/25/2020 12:59 AM, Nenad Filipovic wrote:
Dear Group,

I got a dead P6201 off eBay, and everything points to a defective input FET
(probe serial B065531). So I obtained a handful of MMBF4416 (code
151-5025-00 in the service manual, factory default for later serial
numbers). Tek also released a product modification document under
050-1413-01 code:

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/050-1413-01.pdf
same document:
http://hakanh.com/dl/docs/kitinstructions/050-1413-01.pdf

outlining this replacement. The problem I have now is that drain and source
of the 151-5025-00 FET in the above document are reversed compared to
MMBF4416. None of the datasheets for MMBF4416 say it's symmetrical, and I
somehow doubt an RF JFET would be without optimizations on the drain side.
This comment however states it is symmetrical:

https://groups.io/g/TekScopes/message/131217

but I see no facts this claim is based on. Does anyone have direct
experience with this particular replacement and D-S polarity? Disassembling
the probe head is a pain, I'd like to get this right on the first go.

Best Regards,
Nenad


Re: 2400 series Test 4 Fail 3,13, 1

GerryR <totalautomation1@...>
 

Craig,
My guess would be that you got an old battery from Mouser. I purchased mine from Mouser a few months back, and it came with no date code stamped on it, so who knows how long its been on the shelf. Mine is still working, however, and the one that I took out with a date code of 07-87 still has its full voltage on it. If my new battery fails anytime soon, Mouser is going to hear about it! The calibration process, as you know is quite a tedious process.
Regards,
GerryR
KK4GER

----- Original Message -----
From: "Craig Cramb" <@Manfromtrane>
To: <TekScopes@groups.io>
Sent: Saturday, January 25, 2020 12:02 PM
Subject: Re: [TekScopes] 2400 series Test 4 Fail 3,13, 1


Dealing with 3 scopes all having the Test4 Failures
2465A S/N B011512 Test4 Fail 3 (Fixed)
2465B S/N B010817 Test4 Fail 13 ( This Post)
2465A DM S/N B010824 Test 4 Fail 2 (Haven’t started)

Thank to all for the info in this post. This has been long journey but glad to see an underlying condition could be existing.
I’m looking at completing the repair of the 2465B instrument pre 50,000 S/N. Got started on it about 6 months ago troubleshooting with help from members. Did the repair by replacing the U2460 (original part # NEC D4364C-15LL, replaced with part # NEC D4364C-20L) and replaced the Dallas Keeper battery purchased from Mouser.
That was June 2019. Other things took my interest so just now getting back to calibration. After doing the required calibration I kept getting diagnostic
of test 04 fail 13, Test 04 fail 11, Test 06 fail 01, then back to test 04 fail 01. Couldn’t seem to get ahead of it. So did what I should have done before attempting the calibration and checked the battery voltage. Yea I found it at .6VDC. No wonder I’m dealing with these faults.
So now onto why would the battery be drained in 6 months. The old battery I removed that was from the 1988 vintage was in the same condition so I just thought changing it 6 months ago would allow for another 10 yrs. But that wasn’t the case. So tracing thru the circuit there isn’t anything that I see that would allow for a quick drain of this battery. Feeding two IC, an amplifier, and two caps. Not sure how long it took to drain the battery.

Craig


Re: 2400 series Test 4 Fail 3,13, 1

Craig Cramb
 

Dealing with 3 scopes all having the Test4 Failures
2465A S/N B011512 Test4 Fail 3 (Fixed)
2465B S/N B010817 Test4 Fail 13 ( This Post)
2465A DM S/N B010824 Test 4 Fail 2 (Haven’t started)

Thank to all for the info in this post. This has been long journey but glad to see an underlying condition could be existing.
I’m looking at completing the repair of the 2465B instrument pre 50,000 S/N. Got started on it about 6 months ago troubleshooting with help from members. Did the repair by replacing the U2460 (original part # NEC D4364C-15LL, replaced with part # NEC D4364C-20L) and replaced the Dallas Keeper battery purchased from Mouser.
That was June 2019. Other things took my interest so just now getting back to calibration. After doing the required calibration I kept getting diagnostic
of test 04 fail 13, Test 04 fail 11, Test 06 fail 01, then back to test 04 fail 01. Couldn’t seem to get ahead of it. So did what I should have done before attempting the calibration and checked the battery voltage. Yea I found it at .6VDC. No wonder I’m dealing with these faults.
So now onto why would the battery be drained in 6 months. The old battery I removed that was from the 1988 vintage was in the same condition so I just thought changing it 6 months ago would allow for another 10 yrs. But that wasn’t the case. So tracing thru the circuit there isn’t anything that I see that would allow for a quick drain of this battery. Feeding two IC, an amplifier, and two caps. Not sure how long it took to drain the battery.

Craig


Re: Tek 222 Probe ground lead

tekscopegroup@...
 

The probes on the 222 are permanently attached to the scope, so I would think it would be difficult to get just a whole probe, unless coming from a parts unit. I just looked at one of the detachable probe ground leads of my 222 and it does not look easy to find an alternative that fits nicely. But if the ground on both probes is common as it probably should be (not sure the fact that the inputs of this scope can be floated up to some serious voltage would change this) maybe you could leave the one ground cable on the ch1 probe and the if you need to use ch2 on the same circuit with ch1 already connected, chances are you would not need the second ground. I hope someone with a parts unit will be able to help you.


Re: 11801 questions - funny fan noise and light

Chuck Harris
 

Mine is normal until after the scope has been turned on for
about 30 minutes, and then it starts going "Brummm..... Brummm..."

I suspect a capacitor failure, as it is annoying, and would have
caused notice if it were a "normal" condition.

Annoying, though it may be, I can't see how it would cause any
harm... unless it presages a total failure.

What it isn't is a bearing failure, or lack of lubrication. My
fan spins for what seems like half a minute after power is turned
off.

-Chuck Harris

Reginald Beardsley via Groups.Io wrote:

I don't recall mine ever doing that. I'm very sensitive to noise as I investigate anything I can't identify, so I think I would have noticed it.

A fan on one of my HP Z400 workstations was doing that. I shut it down to reduce the heat in the room and when I tried to boot it the fan was dead. I've not had time to correct it yet.

Good luck,
Reg




Re: Mounting and dismounting curve tracer 177 fixture

Chuck Harris
 

To paraphrase the 577 manual on gaining access to the 577's plugin
connector for replacement:

... remove the 4 screws from the bottom cover of the scope. Pay
note that two of the screws are shorter than the rest, and must
be placed in the front two holes...

It seems likely that some technician, at some point in the scope's
life, removed the bottom cover plate from the scope, and scrambled
the screws... thus locking the plugin into the scope.

-Chuck Harris

Gary Robert Bosworth wrote:

Thank you for your assistance. Sure enough, there were 2 screws on the
bottom that locked the 177 in place. I never would have known about this
locking mechanism without your help. Once I removed the screws, the 177
slid out easily. Thank you again for your help.

Gary

On Fri, Jan 24, 2020 at 10:02 AM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Hi Gary,

Oh boy, I once spend hours trying to get the 177 out of my first 577.
Turn the 577 over. There are two screws near the front of the 577 bottom
panel that screw in to the 177 to hold it in place. I suspect they are
there to prevent the 177 from being easily stolen. The 177 will not budge
until you remove them.
Then you can pull it out by the two ground lugs on either side of the
front of the 177. At first it may seem stuck but that is because the
connector contacts of the 577 holds the PC Board of the 177 pretty tight.

Dennis Tillman W7PF

-----Original Message-----
From: Gary Robert Bosworth
Sent: Friday, January 24, 2020 9:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Does anyone know how to mount and dismount the 177 test fixture into the
577 curve tracer? Is there a locking mechanism?

Gary




--
Dennis Tillman W7PF
TekScopes Moderator




Re: Your generosity is STUNNING!

 

Hi Dave,
Fortunately that day is very far off.
Dennis Tillman W7PF
Say, didn't you just post about putting context in replies? ;^)

Jay


Re: 11801 questions - funny fan noise and light

Reginald Beardsley
 

I don't recall mine ever doing that. I'm very sensitive to noise as I investigate anything I can't identify, so I think I would have noticed it.

A fan on one of my HP Z400 workstations was doing that. I shut it down to reduce the heat in the room and when I tried to boot it the fan was dead. I've not had time to correct it yet.

Good luck,
Reg


Re: P6201 probe Q100 FET replacement

 

YES! I'm the OP for the cited post. My P6201 works perfectly with D and S switched using an MMBF4416

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Nenad Filipovic
Sent: 25 January 2020 11:00
To: TekScopes@groups.io
Subject: [TekScopes] P6201 probe Q100 FET replacement

Dear Group,

I got a dead P6201 off eBay, and everything points to a defective input FET
(probe serial B065531). So I obtained a handful of MMBF4416 (code
151-5025-00 in the service manual, factory default for later serial
numbers). Tek also released a product modification document under
050-1413-01 code:

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/050-1413-01.pdf
same document:
http://hakanh.com/dl/docs/kitinstructions/050-1413-01.pdf

outlining this replacement. The problem I have now is that drain and source
of the 151-5025-00 FET in the above document are reversed compared to
MMBF4416. None of the datasheets for MMBF4416 say it's symmetrical, and I
somehow doubt an RF JFET would be without optimizations on the drain side.
This comment however states it is symmetrical:

https://groups.io/g/TekScopes/message/131217

but I see no facts this claim is based on. Does anyone have direct
experience with this particular replacement and D-S polarity? Disassembling
the probe head is a pain, I'd like to get this right on the first go.

Best Regards,
Nenad


Re: P6201 probe Q100 FET replacement

Nenad Filipovic
 

Is the pinout correct if you install it upside down?
Yes, and this is most likely what I will do. But anyway I wanted to hear
from people who already went through this. I just find it strange that Tek
document has it reversed without any comment or regard.


Re: P6201 probe Q100 FET replacement

Michael A. Terrell
 

Is the pinout correct if you install it upside down?

On Sat, Jan 25, 2020 at 6:00 AM Nenad Filipovic <ilmuerte@...> wrote:

Dear Group,

I got a dead P6201 off eBay, and everything points to a defective input FET
(probe serial B065531). So I obtained a handful of MMBF4416 (code
151-5025-00 in the service manual, factory default for later serial
numbers). Tek also released a product modification document under
050-1413-01 code:

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/050-1413-01.pdf
same document:
http://hakanh.com/dl/docs/kitinstructions/050-1413-01.pdf

outlining this replacement. The problem I have now is that drain and source
of the 151-5025-00 FET in the above document are reversed compared to
MMBF4416. None of the datasheets for MMBF4416 say it's symmetrical, and I
somehow doubt an RF JFET would be without optimizations on the drain side.
This comment however states it is symmetrical:

https://groups.io/g/TekScopes/message/131217

but I see no facts this claim is based on. Does anyone have direct
experience with this particular replacement and D-S polarity? Disassembling
the probe head is a pain, I'd like to get this right on the first go.

Best Regards,
Nenad




P6201 probe Q100 FET replacement

Nenad Filipovic
 

Dear Group,

I got a dead P6201 off eBay, and everything points to a defective input FET
(probe serial B065531). So I obtained a handful of MMBF4416 (code
151-5025-00 in the service manual, factory default for later serial
numbers). Tek also released a product modification document under
050-1413-01 code:

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/050-1413-01.pdf
same document:
http://hakanh.com/dl/docs/kitinstructions/050-1413-01.pdf

outlining this replacement. The problem I have now is that drain and source
of the 151-5025-00 FET in the above document are reversed compared to
MMBF4416. None of the datasheets for MMBF4416 say it's symmetrical, and I
somehow doubt an RF JFET would be without optimizations on the drain side.
This comment however states it is symmetrical:

https://groups.io/g/TekScopes/message/131217

but I see no facts this claim is based on. Does anyone have direct
experience with this particular replacement and D-S polarity? Disassembling
the probe head is a pain, I'd like to get this right on the first go.

Best Regards,
Nenad


Re: Your generosity is STUNNING!

Ken Wright
 

Hi Dennis. This has been tremendous response, my personal views are that this group should be secured for the future, after that I would leave it to your  discretion.
Ken Wright    M0KHW

On Saturday, 25 January 2020, 02:21:20 GMT, Dennis Tillman W7PF <@Dennis_Tillman_W7pF> wrote:

Hi Ken,
By now you have probably seen the reason your transaction number wasn't found. PayPal issues you one transaction number and issues me a totally different number. I had no idea this was the case until a few days ago.

Your contribution came through just fine. This is the information I received:
###  DENNIS' LOCAL TIME    $$$      STATUS            CONTRIBUTOR        PAYPAL TRANSACTION
168  Fri 1/3/2020 3:45 AM  $10.20  Ken says keep it  LU27EUKen Wright  5UU92005CL6140032

Thank you for your contribution,
Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ken Wright via Groups.Io
Sent: Sunday, January 19, 2020 2:54 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Your generosity is STUNNING!

Hello Dennis.I cannot see my contribution on your  list ($10.20), PayPal number. 4CT072513H300731W.I am quite happy for you to retain it, I would like to know that you had received it.
Best wishes.Ken Wright  M0KHW




    On Saturday, 18 January 2020, 16:57:15 GMT, Dennis Tillman W7PF <@Dennis_Tillman_W7pF <mailto:@Dennis_Tillman_W7pF> > wrote:

Wrapping up the TekScopes pledge drive, Michael Dunn and I are STUNNED by your generosity and all the positive comments we received. Your contributions have exceeded the $340 paid to Groups.io by almost 1,000%. You sent us 203 contributions totaling $3,341.77!

We agree this is a problem that I will have to fix since it was my bright idea. I did not realize when I sent my request for help that people would be so generous. I wrote, "So I am asking for small contributions". What happened was anything but "small".

Leo Bodnar, a friend, stunned me when he contributed the entire required amount two days later. This was the first sign I should have chosen a synonym such as "tiny" or "teeny" instead of small. It was too late at that point. I could see there was a tsunami headed my way and I had no way to stop it. I think the contributions have finally stopped. The last one (I
hope) arrived three days ago.

Michael and I have decided that this is far too much money for us to keep on behalf of TekScopes. The simplest solution is for us to tear up the checks and return all the PayPal contributions above $10.00 (actually all those above $10.05) over the next few days, with our sincerest thanks. This will result in exactly half of the contributions being kept and half being returned. PayPal allows me to do a total refund very quickly; we considered partial refunds, but the process would take much longer. If, after you receive your refund, you would still like to make a contribution to TekScopes, please don't send more than $10.00. If you do, we'll be forced to spend it on wine and DMMs.

Thank You,
Dennis Tillman W7PF
Michael Dunn VA1XY

As I promised, here is every contribution I received. The four checking account contributions are listed in numerical order by their bank account number. Following those, the 199 PayPal contributions are listed in numerical order by their transaction number. I double and triple checked the PayPal notices that came to me or to my wife, Marian, to be sure I didn't miss any. If I missed your PayPal contribution please let me know so I can find out what happened to it. The most common contribution was $10.00 and the average contribution was $15.94.

CHECKING ACCOUNT
0000*255          $50.00    TO BE REFUNDED
0035*054          $20.00    TO BE REFUNDED
4650*2065        $50.00    TO BE REFUNDED
9179*1067        $50.00    TO BE REFUNDED

PAYPAL TRANSACTION
02079*******9581B    $10.00
03E74*******9033E  $100.00    TO BE REFUNDED
05P54*******33704    $20.00    TO BE REFUNDED 0DV52*******9640N    $20.00    TO BE REFUNDED 0FX24*******0225D    $12.61    TO BE REFUNDED 0GH61*******5321H    $10.00 0H164*******7324J    $5.00
0HP31*******79205    $10.00
0TB16*******6233S    $10.00
0V228*******9483Y    $15.00    TO BE REFUNDED 0WE54*******4492F    $20.00    TO BE REFUNDED
0XD49*******99831    $10.00
0XX33*******5571C    $20.00    TO BE REFUNDED
10F89*******59157    $20.00    TO BE REFUNDED 11D81*******1581M    $25.00    TO BE REFUNDED 13W62*******8082B    $5.00
16621*******82104    $20.00    TO BE REFUNDED
16T81*******89037    $21.00    TO BE REFUNDED 16U30*******4884J    $10.00 17T42*******7831E    $10.00
1C179*******04615    $10.00
1C830*******8112P    $10.00
1KB10*******35308    $10.00
1KC35*******1823E    $10.00
1KK41*******81702    $40.00    TO BE REFUNDED 1MJ87*******7921S    $20.00    TO BE REFUNDED 1PL71*******8194S    $20.00    TO BE REFUNDED
1SF61*******75325    $6.28
1U469*******7321A    $10.00
1UN19*******71331    $21.50    TO BE REFUNDED 1XL88*******0010V    $10.00 21K47*******0942J    $5.00 26M35*******2652B    $20.00    TO BE REFUNDED
26W48*******18439    $10.00
27955*******6435G    $2.00
28784*******31459    $10.00
2AJ63*******9742M    $20.00    TO BE REFUNDED 2BB60*******7284T    $10.05 2C041*******7435F    $15.00    TO BE REFUNDED
2CF51*******55300    $10.00
2GN07*******6691P    $21.36    TO BE REFUNDED 2HA37*******2763N    $20.00    TO BE REFUNDED 2JP56*******9614M    $6.00 2L669*******5001S    $20.03    TO BE REFUNDED 2LL81*******2181A    $10.00 2NX73*******6334E    $25.00    TO BE REFUNDED 2PE83*******8434J    $20.00    TO BE REFUNDED 2R866*******6484Y    $25.00    TO BE REFUNDED
2S663*******60054    $10.00
2UD84*******92512    $20.00    TO BE REFUNDED 2WG55*******8174X    $10.00 30988*******3613G    $10.00 31532*******3440H    $25.00    TO BE REFUNDED 32S52*******3263Y    $25.00    TO BE REFUNDED 33N46*******8874F    $20.00    TO BE REFUNDED 35J04*******2071X    $5.00 37611*******3481X    $30.28    TO BE REFUNDED 38D56*******6900H    $40.00    TO BE REFUNDED
38H00*******74637    $10.00
39503*******91844    $10.00
3C222*******60057    $5.00
3DL81*******49307    $10.00
3DN03*******6580W    $10.00
3HN95*******74316    $20.00    TO BE REFUNDED 3JY75*******0415H    $10.00 3MK47*******8000V    $20.00    TO BE REFUNDED 3ML12*******7670M    $30.00    TO BE REFUNDED 3RW61*******7583B  $110.00    TO BE REFUNDED 3SV52*******0093K    $10.00 3U066*******6064R    $10.00 3W759*******4273V    $10.00
3WN84*******32644    $20.00    TO BE REFUNDED
3X630*******09454    $10.00
43V15*******1315P    $30.00    TO BE REFUNDED 43W14*******2963X    $10.00
4C132*******25402    $20.78    TO BE REFUNDED 4CP43*******1271K    $15.00    TO BE REFUNDED
4E489*******92025    $20.00    TO BE REFUNDED
4GU02*******14949    $10.00
4H892*******5443S    $10.00
4NK97*******39943    $30.00    TO BE REFUNDED 4NS27*******8414L    $20.00    TO BE REFUNDED 4PM01*******5380X    $10.00
4RA41*******16029    $20.00    TO BE REFUNDED
4V179*******50029    $25.00    TO BE REFUNDED 4VU25*******5244C    $10.00 4WE10*******2420U    $12.00    TO BE REFUNDED 4WG41*******2952L    $20.00    TO BE REFUNDED
4XH55*******98246    $10.00
4XM94*******9951L    $20.00    TO BE REFUNDED 4XU29*******2203A    $5.00 52Y94*******9314H    $10.00 53E69*******9450U    $15.00    TO BE REFUNDED 53M48*******1162D    $10.04
54264*******83607    $20.00    TO BE REFUNDED 54350*******3123J    $10.00 56419*******9740B    $10.68    TO BE REFUNDED
57958*******19248    $10.00
57M28*******3463Y    $15.00    TO BE REFUNDED 58J72*******8751M    $5.05 59K74*******6614F    $10.00 59M25*******3721R    $10.72    TO BE REFUNDED 5FC22*******9632C    $10.00 5GA43*******4223M    $5.00 5K650*******2512S    $10.00 5L001*******9890K    $30.00    TO BE REFUNDED 5L631*******0780F    $5.00
5P795*******19647    $20.00    TO BE REFUNDED
5SE25*******18324    $20.00    TO BE REFUNDED
5UP40*******89642    $20.00    TO BE REFUNDED
5UU92*******40032    $10.20
61H86*******4671Y    $15.00    TO BE REFUNDED 61W04*******0651P    $5.00 62172*******4981K    $10.03 62762*******2074B    REFUNDED 64M95*******0450J    $20.20    TO BE REFUNDED 69567*******7993L    $10.00 69G97*******6681W    $5.00 6AX91*******2221W    $10.00 6DC49*******7192J    $2.20
6DY20*******43532    $10.00
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--
Dennis Tillman W7PF
TekScopes Moderator


Re: 7L5 dot frequency reset bug - any clues or a fix?

Dave Casey
 

I can try one in a 7603 at some point in the not too distant future.

Dave Casey

On Fri, Jan 24, 2020 at 10:55 PM Cliff Carrie <cliffcarrie@...>
wrote:

Thanks for the data, Dave.

I guess the only remaining question in my mind is whether the reset bug
ever shows up with a 7L5 in NON-7854 mainframes.

Now I have to start chasing the two apparent design errors more in-depth.
My 7L5 is now in bug-free condition except for the "reset" and "below 10KHz
display" errors. I have two extender cables. Time to do some serious
debugging.

Cliff Carrie




Re: Mounting and dismounting curve tracer 177 fixture

Gary Robert Bosworth
 

Thank you for your assistance. Sure enough, there were 2 screws on the
bottom that locked the 177 in place. I never would have known about this
locking mechanism without your help. Once I removed the screws, the 177
slid out easily. Thank you again for your help.

Gary

On Fri, Jan 24, 2020 at 10:02 AM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Hi Gary,

Oh boy, I once spend hours trying to get the 177 out of my first 577.
Turn the 577 over. There are two screws near the front of the 577 bottom
panel that screw in to the 177 to hold it in place. I suspect they are
there to prevent the 177 from being easily stolen. The 177 will not budge
until you remove them.
Then you can pull it out by the two ground lugs on either side of the
front of the 177. At first it may seem stuck but that is because the
connector contacts of the 577 holds the PC Board of the 177 pretty tight.

Dennis Tillman W7PF

-----Original Message-----
From: Gary Robert Bosworth
Sent: Friday, January 24, 2020 9:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Does anyone know how to mount and dismount the 177 test fixture into the
577 curve tracer? Is there a locking mechanism?

Gary




--
Dennis Tillman W7PF
TekScopes Moderator



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


Re: Your generosity is STUNNING!

 

Hi Dave,
Fortunately that day is very far off.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of DaveH52
Sent: Sunday, January 19, 2020 12:33 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Your generosity is STUNNING!

Maybe ask for just one dollar next time.
Enjoy your new DMM!





--
Dennis Tillman W7PF
TekScopes Moderator