开云体育

The shipping has now gone up. It's now $59.70. I used to want one of
these printers and they were difficult to find but I think I'm over that
now so I'll pass. But FWIW it appears to have both a Centronics and an
HP-IB interface.

On 2021-04-29 6:31 p.m., Keith wrote:

Not sure how popular these HC100 still are - but the price is right... $15.00 plus shipping at $45.

Here:

Not me by the way - just reporting it in case anyone is looking for one.

I'm looking for the GPIB interface board to one. Can swap for the RS232.

Getting pens for these is pretty challenging, they're special for this
plotter and the way it's designed you can't really use anything else.

--Toby

Cheers,

Keith

For many years test equipment had minimal safety requirements. Newer equipment often has "sacrificial" resistors in parts of the circuit that also function as fuses. They often run hot and fail without reason. Usually the prints will have a label on them, calling them a "Critical Safety Component". Could the resistor you see overheating be one of these?

? Bruce Gentry? KA2IVY

Not sure how popular these HC100 still are - but the price is right... $15.00 plus shipping at $45.

Here:

Not me by the way - just reporting it in case anyone is looking for one.

Cheers,

Keith

Actually the manual says these are 0.125 watt. I'm not familiar enough with TRW resistors but that would indeed be under rated. So interesting to say the least.

The actual power dissipation would be around 1/4 watt so 1/2 watt is safe.

Well a half watt would be good enough.

I don't know the history of this unit. If you look closely you will see that someone was tweaking the pots. Could of been a slip of the probe.

True t’ing!!

My Congressional campaign website got blacklisted by spamhaus in 2006 because one website on my provider Texas.net was forwarding SPAM.

I switched to a more reputable provider forthwith. And instead of serving up SPAM they served up large-breasted NASCAR lady drivers.

Hey, here’s some advice. If you ever run for political office and you have a website, you have to park the website and all its aliases until after you die, because it’s a sure bet somebody will pwn the URL and put a XXX pr0n site there.

Have a nice day.

Jim N6OTQ

Sent from my quenched-gap spark transmitter.

The cap cans themselves complete part of the circuits. What I'd do is to get the same value caps that will fit inside the empty cans (or on the bases). The cans can be cut open with a tubing cutter, or just by spreading the crimp at the bottom, then pulling the guts out. And yes you need a good dose of heat to melt the solder. Suck/wick out as much as you can, then go around and heat the tabs individually and work them out by wiggling a little as you go around with the iron.

On Wed, Apr 28, 2021 at 04:57 PM, Dennis Tillman W7pF wrote:

At least one or two of them look like TV CRT

If I were in Portland... I'd pick them up.
At least one of the tubes was made by the Electron Tube Corporation (an early maker... circa 1948... or multi-beam... CRTs and oscilloscopes... some with more than four!) The one CRT I'm thinking of looks to have multiple cathodes.

--
Roy Thistle

Mark,

Obviously this resistor is underrated in wattage. Something like 1 ow 2W would be better. If a resistor looks like this, it should be a higher wattage. I have seen this problem of a overstressed resistor go up in value or open causing the same problem you have/had. An easy way to get the power needed is to parallel or series resistors, when possible. Sometimes getting the precision resistor in the wattage needed cannot be done with one resistor. You can use an 82 ohm 1 or 2W resistor in parallel with a 4700 ohm. That will give you 80,5938.,. ohms. Well within the 1% tolerance. This is provided you use 1% resistors or measured ones. Your plug-in is worth getting right because it is a rare piece. It looks in excellent condition.

Mark

Finally, it's all done, over 100 Tek mechanical and electro-mechanical items all photographed, identified and posted up on the stuff season page. There are some interesting bits there, from the skinny BNC nuts needed on a few scopes to attach the vertical input connectors, current probe housings and switches, case feet and panel latches, power switch tie-rod couplers, curve tracer parts to reed relay coils. You can see it all here:



No, it's not in numerical order, that's just how it turned out, so you can just go "control-F, then type in the part number you want" in your browser, and it will find it.

A lot of work, and many items are free (how can I charge for a setscrew?), so I am not sure it was time productively spent, BUT if it clears out these items, then susan will be happier, so that works for me.

all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.

So I confirmed that this amplifier should work normally when in the local mode. I also confirmed that this mod would only work on a 7704A with MOD 515C.

Back to the problem... In general the unit had low gain and when you use the Position control it would simultaneously adjust the gain of the applied signal higher at both extreme ranges of the control.

Solution: R705, bias resistor for the signal splitter amp, was out of spec. Was supposed to be 80.6 ohms but measured about 119 ohms. It was slightly discolored, see my photos... /g/TekScopes/album?id=263432

All in all good entertainment I would say.

Hi,

I bought just the PS, and no scope with it, and yes I ran it on 230VAC, but in this 230VAC part of the world, it is usually the RIFA's in the net entrance that give problems.
I already removed these :-) and recapped the Power Supply.

However, I ran the PS not in a scope, but just with using a dummy load.

It's my experience these Power Supplies are quite robust, and don't give many problems in general.

In my effort to repair this PS, these are the parts that are definitely broken.
I ordered replacements and marked these in pink in this picture :-)

/g/TekScopes/photo/263466/3216014?p=Created,,,20,2,0,0

To be continued,

Leo

Problem with spamhaus is it would appear that it only takes one email to them saying a domain is a spam source and they block it without investigation. ?

D.

Groups IO sent me a message the other day complaining that my mailer was bouncing messages and they were suspending email until I unbounced it.

Turned out my mailer was bouncing their mail because they were on one of the spam blocklists. I sent a note to support and it seems to be cleared this morning. Did this happen to anyone else?

I don't use anything exotic, just the sbl from spamhaus.org

I think you need to first create a new album and upload the photos separately.
Then put a URL link to the photos or album in your message.

One important thing to remember is that CB channels below 24 are NEITHER contiguous nor numerically ordered. So to repurpose these switches, you might set up an LED matrix to show continuity per switch position.

I’ve seen a few switch tables for CBs but it was decades ago. I’m pretty sure but not positive that all 40-channel CBs used a switched digital PLL and VCO arrangement and not the “rock crusher” crystal mixer common with most 23-channel rigs.

FWIW the digitally controlled rigs used an octal +1 switch matrix on the VCO, but some had hex inputs. Some also had a ROM to block non-permitted frequencies. Defeating the ROM was non-trivial and required significant surgery.

If CBTRICKS.com is still online, you may be able to garner more info there. Especially if you are converting CBs to other bands, you want to buy their DVD set if it’s still available.
It’s much faster to search a DVD than to download from their website, especially since some misguided anti-CB dweebs continue to engage in DoS attacks against them, 30 years after the CB wars ended.

73
Jim N6OTQ

Sent from my quenched-gap spark transmitter.

To All - I did not post that link.? Dont know where that came from.? i have not posted anythin to this list for a few months.
73,
Bill WA2DVU

I had to install the position potentiometer - it is missing - and therefore it must be the "upper and lower sreen switch" removed.
No idea, how the removement works? No scew, nothing?
I need your help.
Thank you very much!
Regards
Manfred

I bet this scope was originally being used at 120V mains, and the protection was barely being able to cope with the fault. But once put on Euro 240V it definitively was too much for the PS.