I’ve been using the WBT solder on all my Tek repairs and have had zero issues. But I bought my 1/2lb when it was $50 cheaper. And still have over half of it left.

Hi Jim. Always glad to encounter someone using tube scopes in this day and age. I design and troubleshoot with tube scopes as well, although I often reach for the 2465A. Now it would be hard to find a Tek scope that could not be used for audio work. My personal preference is for the 502 or 504. The 504 is cheap, nice and portable, and offers adequate bandwidth. There is no fan so they are very quiet. On the downside they of course are single channel. The two channels of the CA are often very useful. The 530 series, the 531 and 535 both are good scopes for low frequency work, having a 15 MHZ bandwidth. However they do constitute a lot of scope for the application. They are big, heavy to move around, and noisy. They both are fairly complex, especially the 535 with delayed sweep, which I did not find very useful but it is there if you need it. It is tricky to find one that doesn’t have its problems, especially considering the age. If something goes wrong fixing a problem can be tricky. Also getting one shipped without damage can be a challenge. But with say a CA plugin they are a fine instrument. They originally came with a 6006 10X probe, which I use with most of my scopes. I have a lot of parts for these scopes, so if you do get one let me know if you need something. Best regards.

The handbook for the scope should tell you its input impedance which will tell you what probes it can use. Typical scopes have 1 megohm input but not all. Probes can provide voltage range extension which is accompianed with increased impedance, i.e. a 10X probe will give you 10 meg impedance. Probes usually also have some means of compensating for capacitance, usually an adjustment on the probe to optimise its square wave response. Beside scope specs also see the catalogs for probe specs.
Now, if you are going to explore vacuum tube amplifiers you absolutely need the "Radiotron Designer's Handbook" 4th edition. Available several places on the web for example:
<http://www.tubebooks.org/Books/intro_RDH4.pdf>
Books on this site are very well scanned and complete. They are free.
Actual hard copies are still available, do a web search. Personally, being quite old fashioned I prefer hard copy actual books but must settle for electronic versions where the originals are not available or are too expensive.
Earlier editions of the Radiotron are of historical and some practical insterest, the 3rd edition is available at the same site:
<http://www.tubebooks.org/Books/intro_RDH3.pdf>
There will never be another book like the 4th edition, an excellent compilation of audio design at about the end of the vacuum tube period.
BTW, I also have the original Australian edition (in hard copy) and the American edition has everything and is excellently reproduced so there is no advantage to searching out an original.
I bought a 4th when they first came out and wore it out. I have since gotten two used ones beside the PDF version.
Lots of other tube audio books at Tubebooks.org
I wonder why the Tek 535A is considered so good for audio?

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Jim
The Tek catalog from March 1967 is what you need. I've had one for years and its one of the best single references for the 500 series stuff that you will find. I see its available on Tekwiki - lots of data on appropriate probes and plugins.
DaveB, NZ

Hi, everybody.
So at some point I will take the plunge into vacuum tube audio, and according to George Lydeck on this group, the Tek 535A is the best scope ever for tube audio work.  Now, I figured out that the letter series and 1- series plug-ins, although not all of them, are the ones to plug into this mainframe.  I have that stuff on my Test Equipment Wishlist already.
OTOH, plugging directly into scope or plug-in inputs (assumed BNC, since I don't really want to go down the rabbit hole of UHF connectors) is probably not going to be productive, so I will need some probes.  Type N, SMA, 3.5 mm, BNC, and TNC are quite enough variety in my garage lab, thank you very much.

Try as I might, on TekWiki and the Internet at large, I cannot find anything specifically saying which Tek probes are appropriate for a vacuum tube scope such as the 535A.  Maybe this is tribal knowledge?  AFAIK, I have not used a scope with more than 1 tube, the CRT, (I was born in 1965, approaching 60 years old early in 2025), so the world was mostly solid-state by the time I was old enough to be playing around with scopes.  Come to think of it, all 5 of my current scopes have CRTs, and I don't think I've owned one yet with an LCD screen.  I'm in the 'tween generation, I guess.
Any recommendations for probes for a 535A?  Plug-ins also would be a good idea to know for the wishlist.
Thanks a bunch!
Jim FordLaguna Hills, California, USA

For AudioPhools, it also MUST contain micro ground meteorite powder gathered in the dark of the moon  by stygian witches. :)

      Bruce Gentry, KA2IVY

Never could find a product specification PDF... "Halogen free flux"
is about all.

I can say I have used it on assorted Tektronix ceramic strips,
successfully. (Re a 575 mostly, few other odds and ends here and
there.)

I'm in Dayton, Ohio, and Parts-Express is local to me.

I squigged the parts in where I could, and used very little silver
solder, and so I still have most of the 1/8 lb roll I bought some time
ago.

On Mon, Dec 30, 2024 at 7:57 PM Shirley Dulcey KE1L via groups.io
<mark@...> wrote:

Nice to know it exists. I wouldn't have thought to look for audiophile
solder! I wonder what else is in it?

On Mon, Dec 30, 2024 at 7:36 PM David Holland via groups.io
<david.w.holland@...> wrote:

I give you ... not 2%... not 3%... but 4!%, yes four whole percent!.. :-)

https://a.co/d/5nPeVdH

And if you don't like Amazon:

https://www.parts-express.com/WBT-0800-Silver-Solder-4-Silver-Content-1-8-lb.-093-586?quantity=1

(don't read the PE product text too closely, as the audio-phoolery may
cause brain damage.)

That said, AFAIK, WBT is still producing it:
https://wbt.de/produkte/a/detailansicht/Artikel/silberloetzinn.html

Its leaded too. WBT makes a WBT-0805 that's lead free....

(Not cheap tho....)

David

On Mon, Dec 30, 2024 at 7:13 PM Shirley Dulcey KE1L via groups.io
<mark@...> wrote:

The problem is that tin-lead-silver alloys with 3% or more silver is
unobtanium now; nobody makes them any more, likely because of limited
demand caused by the cost of silver. If you want it you'll have to track
down old stock. Tek may recommend 3% or more silver, but surely 2% is
better than 0%.

Lead free solder with 3% silver is readily available; the SAC305 alloy

that

is the most popular lead-free solder fills the bill for that. I'm fond of
the Special Blend solder that Sparkfun sells, with a small amount of
antimony added; it flows a bit better than standard SAC305. But most
lead-free solders have a higher melting point than 63/37 or 62/36/2
(bismuth alloys are the notable exception), so you'll have to work more
carefully with them.

On Mon, Dec 30, 2024 at 6:50 PM Dale H. Cook via groups.io

<bridgewaterma=

plymouthcolony.net@groups.io> wrote:

On 30 Dec 2024 11:15 am, Shirley Dulcey KE1L wrote:

If you would prefer the ease of use of tin/lead/silver solder, you

should

look for Sn62Pb36Ag2 solder.

I am using a similar mix but with 3% Ag, because the Tek service

manuals

specify a minimum of 3% Ag for use on the ceramic terminal strips.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/

Nice to know it exists. I wouldn't have thought to look for audiophile
solder! I wonder what else is in it?

On Mon, Dec 30, 2024 at 7:36 PM David Holland via groups.io
<david.w.holland@...> wrote:

I give you ... not 2%... not 3%... but 4!%, yes four whole percent!.. :-)

https://a.co/d/5nPeVdH

And if you don't like Amazon:

https://www.parts-express.com/WBT-0800-Silver-Solder-4-Silver-Content-1-8-lb.-093-586?quantity=1

(don't read the PE product text too closely, as the audio-phoolery may
cause brain damage.)

That said, AFAIK, WBT is still producing it:
https://wbt.de/produkte/a/detailansicht/Artikel/silberloetzinn.html

Its leaded too. WBT makes a WBT-0805 that's lead free....

(Not cheap tho....)

David

On Mon, Dec 30, 2024 at 7:13 PM Shirley Dulcey KE1L via groups.io
<mark@...> wrote:

The problem is that tin-lead-silver alloys with 3% or more silver is
unobtanium now; nobody makes them any more, likely because of limited
demand caused by the cost of silver. If you want it you'll have to track
down old stock. Tek may recommend 3% or more silver, but surely 2% is
better than 0%.

Lead free solder with 3% silver is readily available; the SAC305 alloy

that

is the most popular lead-free solder fills the bill for that. I'm fond of
the Special Blend solder that Sparkfun sells, with a small amount of
antimony added; it flows a bit better than standard SAC305. But most
lead-free solders have a higher melting point than 63/37 or 62/36/2
(bismuth alloys are the notable exception), so you'll have to work more
carefully with them.

On Mon, Dec 30, 2024 at 6:50 PM Dale H. Cook via groups.io

<bridgewaterma=

plymouthcolony.net@groups.io> wrote:

On 30 Dec 2024 11:15 am, Shirley Dulcey KE1L wrote:

If you would prefer the ease of use of tin/lead/silver solder, you

should

look for Sn62Pb36Ag2 solder.

I am using a similar mix but with 3% Ag, because the Tek service

manuals

specify a minimum of 3% Ag for use on the ceramic terminal strips.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/

I give you ... not 2%... not 3%... but 4!%, yes four whole percent!.. :-)

https://a.co/d/5nPeVdH

And if you don't like Amazon:
https://www.parts-express.com/WBT-0800-Silver-Solder-4-Silver-Content-1-8-lb.-093-586?quantity=1

(don't read the PE product text too closely, as the audio-phoolery may
cause brain damage.)

That said, AFAIK, WBT is still producing it:
https://wbt.de/produkte/a/detailansicht/Artikel/silberloetzinn.html

Its leaded too. WBT makes a WBT-0805 that's lead free....

(Not cheap tho....)

David

On Mon, Dec 30, 2024 at 7:13 PM Shirley Dulcey KE1L via groups.io
<mark@...> wrote:

The problem is that tin-lead-silver alloys with 3% or more silver is
unobtanium now; nobody makes them any more, likely because of limited
demand caused by the cost of silver. If you want it you'll have to track
down old stock. Tek may recommend 3% or more silver, but surely 2% is
better than 0%.

Lead free solder with 3% silver is readily available; the SAC305 alloy that
is the most popular lead-free solder fills the bill for that. I'm fond of
the Special Blend solder that Sparkfun sells, with a small amount of
antimony added; it flows a bit better than standard SAC305. But most
lead-free solders have a higher melting point than 63/37 or 62/36/2
(bismuth alloys are the notable exception), so you'll have to work more
carefully with them.

On Mon, Dec 30, 2024 at 6:50 PM Dale H. Cook via groups.io <bridgewaterma=
plymouthcolony.net@groups.io> wrote:

On 30 Dec 2024 11:15 am, Shirley Dulcey KE1L wrote:

If you would prefer the ease of use of tin/lead/silver solder, you should
look for Sn62Pb36Ag2 solder.

I am using a similar mix but with 3% Ag, because the Tek service manuals
specify a minimum of 3% Ag for use on the ceramic terminal strips.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/

The problem is that tin-lead-silver alloys with 3% or more silver is
unobtanium now; nobody makes them any more, likely because of limited
demand caused by the cost of silver. If you want it you'll have to track
down old stock. Tek may recommend 3% or more silver, but surely 2% is
better than 0%.

Lead free solder with 3% silver is readily available; the SAC305 alloy that
is the most popular lead-free solder fills the bill for that. I'm fond of
the Special Blend solder that Sparkfun sells, with a small amount of
antimony added; it flows a bit better than standard SAC305. But most
lead-free solders have a higher melting point than 63/37 or 62/36/2
(bismuth alloys are the notable exception), so you'll have to work more
carefully with them.

On Mon, Dec 30, 2024 at 6:50 PM Dale H. Cook via groups.io <bridgewaterma=
plymouthcolony.net@groups.io> wrote:

On 30 Dec 2024 11:15 am, Shirley Dulcey KE1L wrote:

If you would prefer the ease of use of tin/lead/silver solder, you should
look for Sn62Pb36Ag2 solder.

I am using a similar mix but with 3% Ag, because the Tek service manuals
specify a minimum of 3% Ag for use on the ceramic terminal strips.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/

On 30 Dec 2024 11:15 am, Shirley Dulcey KE1L wrote:

If you would prefer the ease of use of tin/lead/silver solder, you should
look for Sn62Pb36Ag2 solder.

I am using a similar mix but with 3% Ag, because the Tek service manuals specify a minimum of 3% Ag for use on the ceramic terminal strips.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/

Barry,

Clean J/P3032 ends. The coax wire and socket can be dirty even though they look clean. The switch for CH2 that is connected to the collector of Q3031 labeled 7 could be dirty.

Mark

Barry,

Correct. High voltage multiplier.

Mark

My 547 still has it's original roll. Other than requiring two (such an unreliable machine!) tube replacements, it has never required a component replacement.

Yes without transistors is fine.

Craig

Channel 2 will trigger on Channel 1 and External, but it does not trigger on channel 2. This is what I am working on next!

It started working. Not sure, probably an intermittent problem.

On Mon, Dec 30, 2024 at 09:57 AM, Mark Vincent wrote:

multiplier

I assume high voltage multiplier.

Craig,

I had already removed all of the transistors from the boards. Do you want the boards without the transistors? I can provide the pots.

Barry

If you would prefer the ease of use of tin/lead/silver solder, you should
look for Sn62Pb36Ag2 solder. Kester, AIM Solder, and ChipQuik all make it.
Digikey has Kester and ChipQuik in stock. Mouser stocks Kester and AIM.
ChipQuik solder can also be bought from their own website. Kester and AIM
only offer pound rolls; ChipQuik has smaller ones.

Like 63/37, it's a eutectic alloy. It's even nicer to work with than 63/37,
and suitable for general soldering, but it's more expensive because of the
silver content. As always with solder containing lead, use it responsibly
and always wash your hands after working with it.

Once upon a time, Radio Shack sold small rolls of a similar solder. The
revived website briefly had them but they are not currently available. Use
'em if you've got them!

On Mon, Dec 30, 2024 at 7:18 AM Dale H. Cook via groups.io <bridgewaterma=
plymouthcolony.net@groups.io> wrote:

On 29 Dec 2024 9:28 am, Jean-Paul wrote:

The Tek 500 tube scopes of 1950s...1960s include a small roll of the

original Tek silver soldering for ceramic strip repair

So did the first Tek portable solid state 'scopes beginning in 1966,
which also used the ceramic strips. When I bought my Tek 453 about 1994
the roll was missing, but I already owned a spool of Pb/Sn/Ag solder for
work.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/