I scanned those pages, and processed it up into a PDF.

I'll stick it on KO4BB. If someone wants a direct email I can do
that as well.

I put pages 22, and 23 back also in this collection. (Thanks to Tom
for emailing me back PDF's of 22 and 23.)

David

Dick,?

You should have been around when I moved to Tucson from Boston. To
lighten the load, I gave away about 1/2 my stash. Included were two GR
Variacs with Volt and Amp Meters. One 10 Amp and one 20 Amp. I kept
the third one for my use.

I won't mention the 7 TEK scopes I gave away !!

73, Dick, W1KSZ

One last link, this explains the 50 ohm impedance and measuring RF and microwave frequencies.

Good read!

I have never seen an original Variac. In the 1980s I bought a new
Voltac - by Yokoyama Electric Works Ltd (not Yokohama). This is a 240V
300VA Type B-1, with output to 260V. (Australian mains power is now
230V.) Recently I was able to find, after months of eBay searching
(saved search so I get emails), I obtained a 1500 VA model as well.

These are beautifully made, with fully enclosed metal cases and screw
terminals. Religious folk often deride materialism, but I derive
profound satisfaction and pleasure from owning and using these devices -
as I do my Tek scopes and now two Iwatsu SS-3510 50MHz synchroscopes.

There's a massive 3kVA one on eBay now, in Austin, Texas:



This one looks similar to our 1500VA model:




but is a 2kVA model "130V". They step up a little, so this one probably
has a 120V input. There's a poorly photographed 1kVA model here:



While Googling I found this 1kVA "Matsunaga Mfg. Co. Ltd." "Slide
Regulator" which looks like an earlier design:



I couldn't find any substantial mention of the Yokoyama Electric Works
However, I did find the Matsunaga Manufacturing Company:



with "Slide Regulators" as their first of several product lines. The
Google translation of one of their pages:



indicates the company is based in Yokohama. The company was founded in
1952, has 50 employees and the while the founder is deceased, the
Managing Director is Yoshio Furuya Yosuke Matsunaga.

Perhaps there was a separate Yokoyama Electric company, also in
Yokahama, because a modern Matsunaga product:



looks different in detail from the Yokoyama units, there's no indication
that the company changed its name, and this:



with metal rod handles, is different in every detail from the Yokoyama
models I have and which I have seen pictured on the Net. My units have
no handles, but those pictured on the Net which do have pressed metal
handles.

- Robin

Here's a little reading material.
It'll help you understand why using terminators and matching impedance, plus using attenuators, is a good thing.







Basically to keep "ringing" from distorting your signal the transmission (coax) needs to have the same impedance(ohms)on both ends, the input and at the end connected to the DUT. Otherwise you will get part of the signal you sent from your signal generator reflected back to it which will affect the waveforms. Same as having too much SWR on a CB radio.

You can build your own pads to match the impedance and attenuators.
Here's an attenuator, with pads, that I built, along with some links to the information behind it.

On Tue, 22 Jan 2013 13:04:27 -0800, Steve Purcell
<steve.purcell.k@...> wrote:

Hi All,

I'm getting set up to work on tube equipment and I'm under the impression
that with old and unknown tube instruments it's best to bring up the
voltage slowly using a variac while monitoring the current for anything
unexpected.

Does that sound reasonable? As an integrated circuit guy I wouldn't have
thought that very useful but perhaps it is for tube circuits.

I have never worked on tube equipment where I thought it was
necessary. I usually use my variacs for power supply troubleshooting
where I already know something is not working correctly.

Another question I have is about what variac to purchase. There are some
cheap Chinese ones on e-bay but the real thing appears to be 10 times the
price. Since I'm just a hobbyist would the cheap Chinese one work well
enough or should I search for a used one of higher quality since I can't
afford a $900 Variac.

I pick them up used at garage sales, swap meets, and Craigslist and
build an enclosure if necessary. None of mine have meters as I have
found the dials to have fine accuracy. In one case I ground a
replacement brush from the carbon rod of a carbon-zinc D battery.

开云体育

In order to ascertain serial number coverage of most Tektronix manuals (other than what you see on the front cover from time to time) Look at the parts list sections and the change sections

The 10000 series numbers are for units manufactured in Guernsey, Unfortunately neither of my 465B manuals list any info on Guernsey units . The break point for the two USA manuals occurred at serial B06000 ( Beaverton Built) which occurred in early 1982. The USA manuals may be? useful for the 10000 series with minor differences in some areas. I would look at the date codes on the caps and transistors to get an approximate extimation of the date of manufacturer and then try a USA manual based on the info above (i.e. before or after early 1982)

Dave
"Service? Manual Forensic Anthropologist"
ArtekManuals.com

TIP: Chris I have changed the subject line on this thread to get you more specific help than the generic one you posted

On 1/22/2013 2:04 PM, Bob Albert wrote:

?

I have an original manual for that model, no serial number on it.? But it's not free; I was keeping it for reference but might be willing to part with it for maybe a trade of something or just money. Bob --- On Tue, 1/22/13, chrisfordbell wrote: From: chrisfordbell Subject: [TekScopes] Service manual To: TekScopes@... Date: Tuesday, January 22, 2013, 11:57 AM ? Does anyone know where I can get a free service manual for a 465B scope, ser no. 104467?

-- 
Dave Henderson
Manuals@...

PO Box 175
Welch,MN 55089
651-269-4265

Here's the pattern I use:



I use long bare #12 wires, about 10 inches long with standoffs formed
at the PC end. That way I can thread the new cap into position
without taking the entire scope apart.

Works great as long as you do not damage the board while taking the old caps out.

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows

Here's the link to the pics:

I want to replace electrolytics in my 475 and not to worried about keeping the old cans. I have seen reference to using a "daughter" board to make the grounding through A9 with a modern radial lead mounted on top of the daughter board. Sounds quite neat and was looking for advice.
Thanks.

--- In TekScopes@..., Steve Purcell wrote:

Hi All,

I'm getting set up to work on tube equipment and I'm under the impression
that with old and unknown tube instruments it's best to bring up the
voltage slowly using a variac while monitoring the current for anything
unexpected.

Does that sound reasonable? As an integrated circuit guy I wouldn't have
thought that very useful but perhaps it is for tube circuits.

Another question I have is about what variac to purchase. There are some
cheap Chinese ones on e-bay but the real thing appears to be 10 times the
price. Since I'm just a hobbyist would the cheap Chinese one work well
enough or should I search for a used one of higher quality since I can't
afford a $900 Variac.

Thanks in advance
Steve

Steve,
This has been discussed MANY times in this forum. Search on the messages for "variac". Consensus is that use of a Viarac is a bad method for anything with a SWPS in it. For linear supplies, there are two camps - use the Viarac to protect the caps, or - just plug it in and look for smoke. I am in the second camp. In turning on over 75 old scopes, some for the first time in decades, I have never had a cap short. Maybe I am lucky.

Important- if you see smoke, avoid the almost impossible instinct to instantly cut the power switch. If a resistor is burning, give it a few seconds to actually burn. Carbon comps smoke quite a bit before they discolor enough the find them once the power is off.

Surplus viaracs can be had for an affordable (but not cheap) price, especially if they are just the raw Viarac and not mounted in a box with a nice voltmeter. Be sure to get one with enough power capability for what you want to test. Old vacuum tube scopes can use up to 1000 W. If searching, also use the term "powerstat" a competitor's trademark for a variable autotransformer.

- Steve

As mentioned, the most common P6042 (and A6302/TCP202) failure is a broken transformer. If you drop the probe from a table height to a hard floor (not carpeted), there is a very high likelyhood that the transformer is ruined.

Well, data point - I have 2 P6042s and I had 2 bad cables and no bad
transformers. I think the cable design was so bad that the probe
usually stopped working and was put away before the transformer could
get damaged.

Variac was a trademark of the General Radio Company. There are also Powerstats out
there.

There are several over on the "evil empire", just search on "Variac". Don't gamble your
priceless antique on something of questionable pedigree.

73, Dick, W1KSZ

On Tue, Jan 22, 2013 at 2:04 PM, Steve Purcell
<steve.purcell.k@...> wrote:

I'm getting set up to work on tube equipment and I'm under the impression that with old and unknown tube instruments it's best to bring up the voltage slowly using a variac while monitoring the current for anything unexpected.

Does that sound reasonable? As an integrated circuit guy I wouldn't have thought that very useful but perhaps it is for tube circuits.

Another question I have is about what variac to purchase. There are some cheap Chinese ones on e-bay but the real thing appears to be 10 times the price. Since I'm just a hobbyist would the cheap Chinese one work well enough or should I search for a used one of higher quality since I can't afford a $900 Variac.

The Chinese variacs I've checked out have been OK. You would probably
want to derate them a bit, especially for extended use.

On the other hand, used ones often go for not-unreasonable prices on
eBay, for example:



Also, you'll almost always find well-priced variacs at hamfest swaps.

--- In TekScopes@..., "klauszietlow" wrote:

I bought three P6042s over the last few years and all of them had cable failures. Tektronix did a lousy job on the strain relief where the cable enters the enclosure. I just shortened the cables to get rid of the faulty sections. None of the transformers were broken, but maybe I was just lucky three times...
Klaus
p.s. I paid about $200 on average for each of these

Klaus,

If you paid $200 each and the seller did not warrant them (no returns), then you are very lucky.

As mentioned, the most common P6042 (and A6302/TCP202) failure is a broken transformer. If you drop the probe from a table height to a hard floor (not carpeted), there is a very high likelyhood that the transformer is ruined.

My general rule is that I only pay a premium price if the seller offers a no DOA warranty. The other Tek product to look out for is sampling heads. S-4 and S-6 heads are very susceptible to ESD blowing the sampling diodes. If someone is selling them as "I have no way to test - no returns" warning bells should go off. I would only consider bidding on one with this condition if it was dirt cheap.

- Steve

Sorry, I should have put a space in all the spots showing ohm measurements, it looks like it say 500ohm, but should be 50 ohm and 75 ohm.
Thanks!

I've recently built a selectable signal attenuator to use with my signal generator.
I needed a 50mVpp square wave to test wave forms on a device's circuits,and my SG has a -20dB adjustable attenuator,but it will only drop the output voltage to 150mVpp on a 50ohm terminated coax.
So I built an attenuator box,with a 50ohm input pad(to match the 50ohm out on my SG) and 5 selectable outputs with:
1) A straight through Zero Ohm(no pad)connection
2) A 50ohm pad(no attenuation)connection
3) A 75ohm pad(no attenuation)connection
4) A 50ohm, -10dB connection
5) A 50ohm, -20dB connection

I used some scavenged parts, some new resistors, made a box, installed 2 sets of T-Section attenuators, and the 50ohm & 75ohm pads, a six position rotary switch and 2 female BNC connectors.
I was going to install an adjustable circuit using a 500ohm pot, but decided I didn't really need it.

I've only tested it up to 200kHz,(on a Telequipment D54 mind you) above that it shows a little distortion on the front edge of the square wave, but for inserting a 1kHz square wave for testing it does a great job, and I can drop the output voltage from my SG to 15mVpp!

Here's some pics I took of the box assembly, I didn't get pics when I wired it up cause I had a photographic issue with my equipment (I was lazy and in a hurry!) :~)

It wasn't that hard to make, didn't cost me ANYTHING! Just took a little time to construct and determine wiring for the rotary switch.

***

Here's a couple links to the information I used to construct this:

there are lots of free versions but they are all image scans, and some not so good.
for the 465B (hi or lo version) i highly recommend:


$5 searchable (OCRed) with schematics.

i normally don't pay for things that are free, but in this case it was well worth the few bucks.