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Re: Way off topic: Radio antennas
I will through in my 2 cents worth: does new scaner has 50 Ohm antenna input? A piece of wire is a high impedance ' antenna.
Regards Miroslav Pokorni james89es <james89es@...> wrote: I know this has nothing to do with Tek-scopes (I do own a RM547, so I do belong "in the club") but I know many of you are also into HAM radio. Here's the story: I bought my mother a new police scanner (from Rasio Shack) for x- mas. She has had scanners for 25+ years. Her old Uniden was 15 years old. The outside antenna is about 20 years old. Problem: When we plug the outside antenna into the new scanner, it CAUSES static and reduces signal strength!! I ruled out the plug on the radio itself by connecting a short piece of cable, and touching the bare wire with my finger. In this scenario the signal is stronger and there's less static when I touch the wire, as I would expect. Once I plug in the outside antenna, however, more static and less strength ... even if I leave the little inside antenna on. They replaced the coax just in case, they used the recommended 50ohm cable - a run of about 30 feet. What would explain this?? Keep in mind that the old Uniden still works fine with the outside antenna. Yahoo! Groups SponsorADVERTISEMENT To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. --------------------------------- Do You Yahoo!? Send FREE video emails in Yahoo! Mail. |
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"J" Plugin
pauledst
I'm mostly a reader of this group as most posters are far more
knowledgable. However in going over my manuals to weed out duplicates and ones that I'll never have hardware for I came across an interesting preview sheet of a "letter series" plug-in. The title is "TYPE J DUAL-TRACE PLUG-IN UNIT". It's printed on semi slick paper, one sided and has a red stripe accross the top with "tentative" in white. There is a picture of a real item with all the right knobs, logo and numbers but the S/N is blank. The specs given are 5 mv/cm, 35 Mc and the usual two channel modes. Near the bottom right is the date 8/63. Near the bottom left is a document control number "A-2186". In looking through my catalogs from 1963 to 1966 and 1971 I find no "J" listed. Stan doesn't list one on his web site. The question: Was this plug-in ever produced? Secondly, Is there a repository or a historian who is collecting these odd bits of literature? Paul |
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Re: Does anyone know what a "TEK 067-0561-01 CALIBRATION FIXTURE" is good for?
Stan or Patricia Griffiths
It was primaily used to produce test patterns for the 601 and 611 Storage
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Monitors. Not really too useful since the 601 and 611 are not too useful . . . Stan w7ni@... Lynn Lewis wrote: I've been looking for over an hour now and can't find anything. |
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Re: WTD: Manual for C1002 Camera (DCS)
Stan or Patricia Griffiths
Last year, I went to a government surplus sale conducted by Levy-Latham in
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central Calfornia and saw pallets with ten 7912s on each one. There must have been at least 15 pallets of them. You had to bid on at least on pallet of them. I put in a bid on one pallet . . . I only wanted one 7912 for my collection. I lost on that pallet, but if I had put that bid on a different pallet, I would have won it. I didn't DARE bid on more than ONE pallet . . . I might have won 20 7912's! There were THOUSANDS of Tek instruments up for sealed bid at this sale. I probably placed 50 different bids. I lost every one of them. It was a fun and interesting trip but a real loser, from a financial point of view . . . for me, anyway. Stan w7ni@... Craig Sawyers wrote: (In the R7912, one long finely focusedI remember this unit well. Back in the late '70s I used this beast to |
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Need Help with 7704A Power Supply
w1ksz
I have picked up a nice clean 7704A mainframe that has a power supply
problem. The first thing I did was check the +5v Lamp voltage and it was very low (~0.8v). I looked at it with another scope and saw a string of widely spaced low voltage pulses (??). It looks like the Frequency Converter section is not oscillating. Any ideas what I can look at ? Failing that, does anyone have a spare Power Supply ? The scope is just too clean to scrap at this point. Thanks, Dick, W1KSZ |
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Re: Does anyone know what a "TEK 067-0561-01 CALIBRATION FIXTURE" is good for?
Lynn Lewis
Thanks. It looks interesting but I'm afraid I've already bought enough
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interesting stuff to keep me busy for a while. Thanks for the info? I'm going to let it pass. -----Original Message-----
From: Jim Reese [mailto:nfeinc@...] Sent: Thursday, January 03, 2002 3:46 PM To: TekScopes@... Subject: Re: [TekScopes] Does anyone know what a "TEK 067-0561-01 CALIBRATION FIXTURE" is good for? It shows up as a raster generator. 16-24 line pairs. 300-400 dots. 1 volt output. The military paid $5800 each for them. It sounds like it may be used for adjusting Tek displays of some sort. Jim Reese --- Lynn Lewis <mrzuzu@...> wrote: > I've been looking for over an hour now and can't > find anything. > > > > > > ------------------------ Yahoo! Groups Sponsor > > To unsubscribe from this group, send an email to: > TekScopes-unsubscribe@... > > > > Your use of Yahoo! Groups is subject to > > > __________________________________________________ Do You Yahoo!? Send your FREE holiday greetings online! To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. |
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Re: Does anyone know what a "TEK 067-0561-01 CALIBRATION FIXTURE" is good for?
It shows up as a raster generator.
16-24 line pairs. 300-400 dots. 1 volt output. The military paid $5800 each for them. It sounds like it may be used for adjusting Tek displays of some sort. Jim Reese --- Lynn Lewis <mrzuzu@...> wrote: I've been looking for over an hour now and can't
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Tektronix 545D
Reed Dickinson
I saw the note from Dean and it brought back memories. I worked for IBM in
1957 to 1959 as bench technician. I used a 541 then a 545. I really fell in love with the 545 and wanted a scope for home use so, I managed to buy a DuMont 304, it was not up to par with the 545. Being spoiled for a 545 but not having the cash available to purchase one and, having access to all the parts, I decided to make one. From 1957 to 1959 I constructed a 541. In 1966 I came across a delay board for the scope and added it, it then became a 545, I call mine a 545D. It has all the features of the 545 with the addition of a running time meter. I wound the original delay line on wood dowels with costume beads for the taps. I later added a factory made delay line. The home made CA and K plug in's are mounted in the upper right rather than the lower left. The mercury pulser plug in got lost during a move. Someday, when I drive up the coast, it is going to Stan Griffiths for his museum. If anyone wants a picture, drop me a line as it is in my garage and still works great. Reed Dickinson S. CA. reed-d@... |
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Re: WTD: Manual for C1002 Camera (DCS)
Craig Sawyers
(In the R7912, one long finely focusedI remember this unit well. Back in the late '70s I used this beast to capture sub-ns detail on laser pulses. The total pulse length was 30ns or so, and the repetition rate was 30Hz - so even a 7103 couldn't give a bright enough trace to see (a duty cycle of 10^-6!!). In addition the detail changed from shot to shot. So I used a C53 camera to sync a single shot from the CRT screen on the unit. In addition it had a video output that I fed to a 15" monitor so I could easily see the effect of adjustments to the laser. It was an extremely useful piece of gear - as you said, there was absolutely nothing on the market that did this sort of thing other than the 7912. Craig |
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Re: WTD: Manual for C1002 Camera (DCS)
Ray Menke
On Wed, Jan 02, 2002 at 11:45:58PM -0000, w1ksz wrote:
I picked up this TEK Video Camera (mounts on Scope face).I believe the whole system was called a DCS (Digitizing Camera System), and included the black/white video camera, C-30 style camera adapter, a long pc board that plugged into a luggable IBM pc, or even a 386, and three ring binder of the software type, and some software on floppies. I made some home videos using this camera tied to the IBM Luggable (dual floppies only), with video going into my VCR. Used as intended, this camera coupled with a microchannel CRT could capture details that eluded ALL the digital scopes of the time. One system was especially good at determining ESD (electrostatic discharge) properties of semiconductor chips. Digitizers couldn't put enough points on a waveform to show any detail, but this DCS could almost keep up with the Scan Conversion techniques used in the R7912. (In the R7912, one long finely focused CRT wrote on the front side of a very small diode array while another crt scanned the backside of the diode array...that is why the R7912 is so long it won't fit in a regular rack cabinet.) I thought I had a box of accessories, including the crazy cables, SW, and manuals...but I can't find it this morning. You might look in some old TEK catalogs...all the stuff I just typed came from memory. -- Ray Menke |
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Blowing line fuses in a 475
Hi David:
I use a variac with an AC ammeter in the load side. Temporarily replace the 475 fuse with a 4 amp one and adjust the AC voltage until about 2-4 amps flow into the scope and wait about 15 minutes. Remove power and immediately feel all the bridge rectifiers, filter caps and the power transformer for excessive heat. The transformer should be warm but if any rectifiers or caps are warm that is the problem. If all the rectifiers and caps are cold and the transformer is warm you might have a bad transformer or a short on the main board. Above all, do nor try to remove the main board, it is a terrible job. An alternate method would be to use the variac but measure the current flowing in each secondary wire going to the main board using a clamp on ammeter. I do not use this method as there is little room for my clamp on ammeter. To remove a defective bridge rectifier bend it back and forth until the leads break. Then solder in a new one. Good luck Reed Dickinson |
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Re: Tektronix 545D
Chuck Miles
Reed,
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I'd love to see the picture of your "545D".,... I have a "B" version. Thanks Chuck Junction City, OR ----- Original Message -----
From: "Reed Dickinson" <reed-d@...> To: <TekScopes@...> Cc: "Reed Dickinson" <reed-d@...> Sent: Thursday, January 03, 2002 11:38 AM Subject: [TekScopes] Tektronix 545D I saw the note from Dean and it brought back memories. I worked for IBMin 1957 to 1959 as bench technician. I used a 541 then a 545. I reallyfell in love with the 545 and wanted a scope for home use so, I managed to buya DuMont 304, it was not up to par with the 545. Being spoiled for a 545but not having the cash available to purchase one and, having access to allthe parts, I decided to make one. From 1957 to 1959 I constructed a 541. Inbecame a 545, I call mine a 545D. It has all the features of the 545 with thedelay line. The home made CA and K plug in's are mounted in the upper rightfor his museum. |
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Re: Help on 485 power supply problems
Sounds like you have a short past the PS. Try to get a manual if you
don't have one before you pull off any connectors. If you do get brave and pull them mark them first. If the ticking stops after you pull some of them then you'll have a general idea of where it's at. If it still ticks the problem is with the PS on the secondary of the power transformer. Could be feedback to primary too but not likely. Good luck with it. Pat --- In TekScopes@y..., Willard G Wood <willardgw@j...> wrote: Any one that can help with my problem on a 485 oscilloscope, I wouldswitching power supply still run, I know removing the coax drive cable to the |
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Re: Lavoie LA-265?
JOSE V. GAVILA (EB5AGV/EC5AAU)
Hmmmm... I was offered locally (I am in Spain and it is really difficult to
locate good Tektronix gear so Lavoie is yet more difficult to find) a Lavoie LA-265A for about $110, along a CA plug-in. I refused to buy it, because I thought a clone was not worth so much. I wonder if I was wrong, due to scarcity of them. BTW, seller told me it worked fine and was in top condition. Perhaps it has the HV transformer already changed ;-)! Happy 2002 to all! JOSE ---------------------------------------------------------------------- 73 EB5AGV / EC5AAU - JOSE V. GAVILA La Canyada - Valencia (SPAIN) EB5AGV Vintage Radio Site: European Boatanchors List: |
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Re: Lavoie LA-265?
Stan or Patricia Griffiths
I have one of those things in my collection and it will be interesting to see
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what I find wrong with it when (and if) I ever get around to it. I also have two clones made by Hickok and I have looked at both of them and they both have HV problems that I believe to be the transformers. In one of them, I got it to work well by transplanting an entire Tek HV assembly into it. I'll bet there is not a stock one still running anywhere in the world . . . Stan w7ni@... deanhuster wrote: During my time in the U.S. Navy at USNAVSECGRUACT Sabana Seca, Puerto |
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Lavoie LA-265?
deanhuster
During my time in the U.S. Navy at USNAVSECGRUACT Sabana Seca, Puerto
Rico in the test equipment cal shop, I got to use the Lavoie "faux- clone" of the Tek 545 every day for two years. I finally got tired of its (and every one of them that I'd seen) problem: bright trace that gradually dims over an hour or two to no trace at all. I finally figured out that it must be the HV transformer so decided to pull a fast one on the Navy and order a Tek replacement rather than the Lavoie part number. Lo and behold, when the mil-packed Tek transformer came it, enclosed was a sheet telling how to install the Tek part in a Lavoie scope! Obviously, this was the premier problem with this "design". We had two of those danged mainframes at the operational site and they both had the same problem. I fixed the second one within a month. Then I saw another one at another duty station and told the techs how to take care of the problem. I remember that the Lavoie scope had a little box filled with a gillion neon lamps, all in series used as a voltage regulator as I recall. And the ceramic strips were little metal clips in ceramic notches rather than the fired silver-on-ceramic that real Tek's had. Once I fixed the scope up, I didn't really have any complaints about its operation but it always bugged me that it was obvious copyright and patent infringement. Later, after I went to work for Tek, we'd gotten the message that the lawsuit against the government, Lavoie, Hickock, et. al. had been "won" by Tek. Dean |
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