Date   

Re: tektronix 7S14 batteries and time base question

 

Hi Miguel,
You hijacked another thread (OT: High Frequency coax?? Copper tubing??)
Start a new thread if you want to start a new subject. It's called "New Topic" in the web interface.

For an explanation of the workings of the 7S14, go here:
http://w140.com/tekwiki/wiki/7S14
and download the Service Manual. See the link below the picture at the right side of the Tekwiki page.

Did you verify the total voltage delivered by your leds? It's best to stay in the range of the original batteries.

Raymond


Re: 465 No Horizontal Sweep

 

On Sun, Nov 3, 2019 at 05:25 PM, david wrote:


Cap C1220 is wet Tantalum
Are you sure that's a wet tantalum in there originally? Don't think so.
I'd say any good quality modern elcap will do. Nothing special there.

Raymond


Re: 546 Trace off screen

Steph L
 

Your thinking is logical.

The next step would be compare actual voltages on the 546 to those given on Power Supply schematic sheet 1 of Service Manual and the Horizontal Amp elsewhere.

You can begin here, if not already known.

http://w140.com/tekwiki/wiki/Main_Page

Steph.


Re: OT: High Frequency coax?? Copper tubing??

GerryR <totalautomation1@...>
 

Thanks Dennis,
After I asked the question I did look up the cable and found out its characteristics. I've spent most of my career (now retired) in industrial electronics / control systems, so some RF stuff still puzzles me. For instance, recently I inquired about a tunnel diode pulser from a person who makes them. He stated that he offered them with SMA connectors; I wanted BNC connectors. He told me that he couldn't get the response with the BNC's that he can get with the SMA's, yet Tektronix offered (at one time) a tunnel diode pulser that had a better response than what he offered, with BNC connectors. Why? Thus, my question as to why the semi-rigid cable is so much better at the higher frequencies? Just curious. Thanks, again; I didn't mean for anyone to do my homework for me.
Best regards,
GerryR
KK4GER

----- Original Message -----
From: "Dennis Tillman W7PF" <dennis@ridesoft.com>
To: <TekScopes@groups.io>
Sent: Sunday, November 03, 2019 4:54 PM
Subject: Re: [TekScopes] OT: High Frequency coax?? Copper tubing??


Hi Gerry,

Every general class ham should have a coax chart at your fingertips somewhere. Personally I prefer the quickly accessible Wikipedia article on Coaxial Cable at https://en.wikipedia.org/wiki/Coaxial_cable. It contains a very detailed chart listing a very large number of coax types and all of the important parameters anyone would need to compare them all.

It says the insulator / dielectric for RG-402 and RG-405 is PTFE (aka Teflon).

Dennis Tillman W7PF

-----Original Message-----
From: GerryR
Sent: Sunday, November 03, 2019 11:15 AM

I'm not at all familiar with this type of coax. What is the core material, and what makes it so good at the higher frequencies?
GerryR
KK4GER

----- Original Message -----
From: "Dennis Tillman W7PF" <dennis@ridesoft.com>
Sent: Sunday, November 03, 2019 1:46 PM

These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used
to. Tools to cut it properly and to bend it properly are expensive. Using
common tools to cut it like a pipe cutter, and to bend it like an
inexpensive bending jig, will almost certainly affect the high frequency
performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is
great stuff provided you don't want to bend it more than once. Though
rebending used cables is OK. The solder filled braid "RG402" has become my
standard cable for anything above 1 GHz. I've made a couple of H field
probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been
documenting my efforts in this thread:
https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now
that I have an APC-7 cal kit and adapters.
Have Fun!
Reg
--
Dennis Tillman W7PF
TekScopes Moderator




--
Dennis Tillman W7PF
TekScopes Moderator


Re: OT: High Frequency coax?? Copper tubing??

 

Hi Gerry,

Every general class ham should have a coax chart at your fingertips somewhere. Personally I prefer the quickly accessible Wikipedia article on Coaxial Cable at https://en.wikipedia.org/wiki/Coaxial_cable. It contains a very detailed chart listing a very large number of coax types and all of the important parameters anyone would need to compare them all.

It says the insulator / dielectric for RG-402 and RG-405 is PTFE (aka Teflon).

Dennis Tillman W7PF

-----Original Message-----
From: GerryR
Sent: Sunday, November 03, 2019 11:15 AM

I'm not at all familiar with this type of coax. What is the core material, and what makes it so good at the higher frequencies?
GerryR
KK4GER

----- Original Message -----
From: "Dennis Tillman W7PF" <dennis@ridesoft.com>
Sent: Sunday, November 03, 2019 1:46 PM

These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used
to. Tools to cut it properly and to bend it properly are expensive. Using
common tools to cut it like a pipe cutter, and to bend it like an
inexpensive bending jig, will almost certainly affect the high frequency
performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is
great stuff provided you don't want to bend it more than once. Though
rebending used cables is OK. The solder filled braid "RG402" has become my
standard cable for anything above 1 GHz. I've made a couple of H field
probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been
documenting my efforts in this thread:
https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now
that I have an APC-7 cal kit and adapters.
Have Fun!
Reg
--
Dennis Tillman W7PF
TekScopes Moderator




--
Dennis Tillman W7PF
TekScopes Moderator


tektronix 7S14 batteries and time base question

Miguel Work
 

Hi,

I have bought a 7S14 with bad batteries. Hi have replaced batteries for leds, but IR, three in series, 0,9 v for led.

https://groups.io/g/TekScopes/album?id=131745


How works delayed time base, is similar to dual time base of other timebases, like 7b52?

Regards

Miguel


-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de GerryR
Enviado el: domingo, 3 de noviembre de 2019 20:15
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] OT: High Frequency coax?? Copper tubing??

I'm not at all familiar with this type of coax. What is the core material, and what makes it so good at the higher frequencies?
GerryR
KK4GER

----- Original Message -----
From: "Dennis Tillman W7PF" <dennis@ridesoft.com>
To: <TekScopes@groups.io>
Sent: Sunday, November 03, 2019 1:46 PM
Subject: Re: [TekScopes] OT: High Frequency coax?? Copper tubing??


These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used
to. Tools to cut it properly and to bend it properly are expensive. Using
common tools to cut it like a pipe cutter, and to bend it like an
inexpensive bending jig, will almost certainly affect the high frequency
performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is
great stuff provided you don't want to bend it more than once. Though
rebending used cables is OK. The solder filled braid "RG402" has become my
standard cable for anything above 1 GHz. I've made a couple of H field
probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been
documenting my efforts in this thread:
https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now
that I have an APC-7 cal kit and adapters.
Have Fun!
Reg




--
Dennis Tillman W7PF
TekScopes Moderator


Re: OT: High Frequency coax?? Copper tubing??

GerryR <totalautomation1@...>
 

I'm not at all familiar with this type of coax. What is the core material, and what makes it so good at the higher frequencies?
GerryR
KK4GER

----- Original Message -----
From: "Dennis Tillman W7PF" <dennis@ridesoft.com>
To: <TekScopes@groups.io>
Sent: Sunday, November 03, 2019 1:46 PM
Subject: Re: [TekScopes] OT: High Frequency coax?? Copper tubing??


These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used to. Tools to cut it properly and to bend it properly are expensive. Using common tools to cut it like a pipe cutter, and to bend it like an inexpensive bending jig, will almost certainly affect the high frequency performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is great stuff provided you don't want to bend it more than once. Though rebending used cables is OK. The solder filled braid "RG402" has become my standard cable for anything above 1 GHz. I've made a couple of H field probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been documenting my efforts in this thread:
https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now that I have an APC-7 cal kit and adapters.
Have Fun!
Reg




--
Dennis Tillman W7PF
TekScopes Moderator


Re: OT: High Frequency coax?? Copper tubing??

 

These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used to. Tools to cut it properly and to bend it properly are expensive. Using common tools to cut it like a pipe cutter, and to bend it like an inexpensive bending jig, will almost certainly affect the high frequency performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is great stuff provided you don't want to bend it more than once. Though rebending used cables is OK. The solder filled braid "RG402" has become my standard cable for anything above 1 GHz. I've made a couple of H field probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been documenting my efforts in this thread:
https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now that I have an APC-7 cal kit and adapters.
Have Fun!
Reg




--
Dennis Tillman W7PF
TekScopes Moderator


Re: OT: High Frequency coax?? Copper tubing??

Reginald Beardsley
 

Ian,

I put together some quick examples for you as I have everything sitting next to me. Have a look at this:

https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/msg2768098/#msg2768098

The Tek 11801/SD-24/SD-26 setup I used has a frequency response to 20 GHz. In the top photo you're seeing the reflection responses for the 3 open cables. The SD-24 produces a <19 ps rise time 100 kHz square wave. The low frequency of the square wave allows testing very long cables. The fast rise time allows testing to 20 GHz.

The lower scope photo shows both the reflection and the thru. Reflection is the shorter step delay and thru the longer step delay.

My first encounter with SMA connectors was an HP 8601A. Because they are small, cheap and have lots of BW they have become the default choice for lots of Chinese modules on ebay.

If you look through the thread you'll see various adapter and connector combinations. The wider the reflection bumps, the lower the frequency that unit can pass. The SMA-F/N-F connector comparisons shows that my ebay Chinese versions are only good up to 1 GHz. But both my rigs only go up to the 70 cm ham band at 430 MHz, so they will do just fine for antenna switching using Radiall ST6P SMA relays.

A bump downwards is capacitive reactance and a bump upwards is inductive reactance. The width of the bump shows the approximate cutoff frequency. At best BNC is usable to 3-4 GHz, but only if they are very good quality and are fairly new. The marvelous thing about TDR, is that every discontinuity appears in sequence from left to right. So you can tell if it's the cable to connector or the connector to connector interface.

Cycle limit on SMA connectors is typically 500 connections. Pretty much all test gear has used SMA internally for connections to the exterior bulkhead connectors for many years. It makes replacing worn bulkhead connectors easy. The exception would be things that go too high to use SMA. At which point the connectors get *very* expensive.

Certainly in my view the question is appropriate here. It's a really fine group of people most of whom also follow the HPAK list. I just wish I could fish an R&S SMS out of the trash. :-)

BTW There is an R&S group in the process of moving from yahoo to groups.io.

Have Fun!
Reg


Re: OT: High Frequency coax?? Copper tubing??

Reginald Beardsley
 

Here's a representative link for the information you're looking for:

http://www.sumlocable.com/sub_product/rg401-rg402rg405-semi-rigid-43.html

There's lots more. This was simply the first one google tossed up. It is great stuff provided you don't want to bend it more than once. Though rebending used cables is OK. The solder filled braid "RG402" has become my standard cable for anything above 1 GHz. I've made a couple of H field probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been documenting my efforts in this thread:

https://www.eevblog.com/forum/rf-microwave/testing-rf-connectors-and-cables/

I will be supplementing the TDR results with 8753B/85046A testing soon now that I have an APC-7 cal kit and adapters.

Have Fun!
Reg


Re: Motorola 2N5928 Power Transistor Data Sheets wanted

Dave Wise
 

Nice of the “vendor“ to have outed themselves. Now we know that *every* Motorola-branded 2N5928 is a fake!

Dave Wise

On Nov 2, 2019, at 9:16 PM, boid_twitty <legg@magma.ca> wrote:

No references to a Motorola 2N5928. Original vendor was PTI
Motorola made 2N6309, with similar ratings.
Both are TO114.

In TO63, JEDEC does not register a single part with >50A or >250W rating, so
Motorola will never have branded that case with that number.

Recheck your info.

RL



465 No Horizontal Sweep

david
 

Hi folks, been long time,My 465 has no horizontal sweep, vertical still working, single dot in center of screen with no input. Vertical line or trace in center with input signal.Checking Horizontal Amp found Resistor R1220 blown,burst, suspect Capacitor C1220 is shorted, but not certain.Can you help me troubleshoot ?
Cap C1220 is wet Tantalum, can I replace with other type cap ? Electrolytic, Ceramic, dry Tantalum ?
David


Re: Motorola 2N5928 Power Transistor Data Sheets wanted

boid_twitty
 

No references to a Motorola 2N5928. Original vendor was PTI
Motorola made 2N6309, with similar ratings.
Both are TO114.

In TO63, JEDEC does not register a single part with >50A or >250W rating, so
Motorola will never have branded that case with that number.

Recheck your info.

RL


Re: 468 With Odd Trace Timing issue when in Vertical ALT Mode Only.

DaveH52
 

It was just a guess. I saw a cable going to the trigger input.


Re: 2465 HV Power Supply Issue

DaveH52
 

Siggi,
Thanks for the reply!
It wasn't the fuse.
The problem was the idiot (me) that put it back together. I managed to bend the pin on the -15V Unreg output when I mashed the connector on.


Re: Picked up my first tek scope

Jamie Ostrowski
 

Hi Noel,

Congrats on your first Tek scope!

There is a wealth of great documentation on the Tek wiki, including your
manual.
http://w140.com/tekwiki/wiki/454

There are manuals for your unit on the right hand side you can download.

73's,

- Jamie

On Sat, Nov 2, 2019 at 10:24 PM pondo via Groups.Io <eggman69_us=
yahoo.com@groups.io> wrote:

Hello everyone. I just joined this morning. My name is Noel and I am from
west Tennessee. I’ve been looking for a Tektronix scope for a little while
now. I am a ham radio operator and want to learn to repair some of my older
gear.

I picked a 454 scope at the Chattanooga hamfest 2 weeks ago. It did not
come with any probes. I picked up a set of p6010 probes and a set of p6011
probes. The tek probes do not have the hooks or clips with them. I also
ordered a set of Chinese 100 MHz probes.

Is there anything thing else I need for the scope? I know I need a manual.
I’m new to scopes and a complete newb.

73’s kj4unx Noel




Re: Manuals

Wojtek Krzywicki
 

Thans!!
Ciasteczkowypotwor!! :)


Picked up my first tek scope

kj4unx
 

Hello everyone. I just joined this morning. My name is Noel and I am from west Tennessee. I’ve been looking for a Tektronix scope for a little while now. I am a ham radio operator and want to learn to repair some of my older gear.

I picked a 454 scope at the Chattanooga hamfest 2 weeks ago. It did not come with any probes. I picked up a set of p6010 probes and a set of p6011 probes. The tek probes do not have the hooks or clips with them. I also ordered a set of Chinese 100 MHz probes.

Is there anything thing else I need for the scope? I know I need a manual. I’m new to scopes and a complete newb.

73’s kj4unx Noel


546 Trace off screen

ethanfg99@...
 

Hey all,

I just acquired a 546 and tested it out for a couple hours. After shutting it off and turning it back on later, the trace disappeared as I was using it. It wasn’t gradual, the trace instantly disappeared and the scope says that it’s off the screen to the right. Turning if off for a while and then back on or changing any settings has no effect. I was having issues with the power on delay relay, and narrowed it down to bad contacts on the relay. After cleaning them the scope powers on normally but has this issue. Could this be from lack of power to a portion of the scope? I know the relay switches many different circuits - maybe it’s not switching on the power for the horizontal amp?

Any input would be greatly appreciated.


Re: OT: High Frequency coax?? Copper tubing??

Jeff Kruth
 

Called "Semi-rigid coax" usually 50 ohm, diameters of .250,.141,.085 &.047 inch are fairly common and have connector families available. There are other sizes and impedances, of course. Very common in microwave-UHF gear. Made by Uniform Tube (UT-141 is very common) and others. Now a re-bendable style has become common, called "reformable" basically began as solder filling coax braid. 

Jeff Kruth
Hope this helps.

In a message dated 11/2/2019 8:02:34 PM Eastern Standard Time, iacbell@outlook.com writes:
Hi,This question is related to my Rohde and Schwarz SMS Signal Generator (rescued from a Rubbish Dump).  There is some type of coax or copper tubing in this Signal Generator which I am unsure about.  There are several photos in the following Album ...  https://groups.io/g/TekScopes/album?id=130642 ....  specifically photo "Rohde and Schwarz.... 1007"  Although this is not related to my current problem with its PSU, I would like to understand what this tubing is. My Google searching has led to discussions about limitations of coax and BNC's, and waveguides at GHz frequencies etc, but I do not understand this in the context of a 520MHz Signal Gen and that the the lower tubing in photo "1009" terminates on the rear panel at a BNC.Any explanations or 'pointing me in the right direction' would be appreciated.My apologies if this is too far off-topic, but this is one Forum I trust where the appropriate expertise resides..-- Cheers,Ian,Melbourne, Australia

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