Re: 8590B low sensitivity problem
Sam,
I haven't seen an email. I'll avoid applying DC to the 1st mixer, thanks for the reminder.
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Re: 8590B power supply repair
My parts list is 2 x 470uF Electrolytics, 1 bridge rectifier, 1 class X 0.6uf and 2 class Y 4n7. Mine was obvious as one of the electrolytics split whilst iunder power and one of the class Y caps was black and sooty. The bridge wasn't short circuit but had high reverse leakage current.
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Re: [test-equip-trader] 8671, 8672, 8673 support kit
toggle quoted message
Show quoted text
I just bought one on EBay for $100.00 plus shipping. I was the only
bidder.
Glenn
On 12/5/2020 12:05 PM, Pete Manfre
wrote:
For sale is my service support kit for the
867x series signal generators.? ?Has all adapters,? board
extenders,? adapters,? manual,? and service board.? ?A must
for easy diagnosis and repair.? Foam has severely deteriated
and will be removed before shipping.? ?Parts will have to be
cleaned.? ?$550 shipped CONUS¡ outside US additional
shipping cost.?
Payment¡ cash in person,? check on US bank,?
western union,? and bank transfer.? ?No paypal
Location.? .. Ft. Mill,? SC,? USA 29707
More pics svailable
Pete wa2odo_._,_
--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
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Re: [test-equip-trader] 8671, 8672, 8673 support kit
I just bought one on EBay for $100.00 plus shipping. I was the only
bidder.
Glenn
On 12/5/2020 12:05 PM, Pete Manfre
wrote:
For sale is my service support kit for the
867x series signal generators.? ?Has all adapters,? board
extenders,? adapters,? manual,? and service board.? ?A must
for easy diagnosis and repair.? Foam has severely deteriated
and will be removed before shipping.? ?Parts will have to be
cleaned.? ?$550 shipped CONUS¡ outside US additional
shipping cost.?
Payment¡ cash in person,? check on US bank,?
western union,? and bank transfer.? ?No paypal
Location.? .. Ft. Mill,? SC,? USA 29707
More pics svailable
Pete wa2odo_._,_
--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
|
Workaround for 4396A power supply failure
I've had a dead 4396A sitting on my bench for a number of years. Recently I found an excellent thread (started 9/2020) on a Dutch forum that gave me enough information to finally fix my partially failed Toko 04396-61040 A40 pre-regulator module. Use Google Chrome to open this link and it should give you an option to translate Dutch to English (or another language)
?
Lots of good photos here and partially decoded schematics. My contribution was to figure out how to bypass the "shutdown 2" signal on the second switching regulator as a quick fix (see the A40 block diagram in the related 4286A service manual). Although you lose fan rotation and +5V overvoltage protection I didn't judge that to be a major issue in my case. The root cause was probably a bad opto or SCR but I didn't take the investigation that far.
?
Also in that thread is a discussion of replacing the A40 Schaffner mains input module when the internal caps (RIFA brand no doubt) let out the magic smoke. I've had this happen on the 4396A and also an 8657B.
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On Saturday 05 December 2020 11:17:46 am Jeremy Nichols wrote: I have purchased and used these capacitors; they are excellent. In many
cases, however, I find it is easier and less expensive to abandon the old
capacitors in place and install new ones below the chassis where they are
out of sight. With some exceptions (military, for example), vacuum tube
equipment from the heroic age usually has space ¡®below the line,¡¯ making
installation easy.
Jeremy This has been exactly my approach as well, when I was into doing that sort of work... On Sat, Dec 5, 2020 at 6:09 AM Eric Boyle via groups.io <k0elb=
[email protected]> wrote:
Here's their sales website:
-- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: 9122 and 9122C - HPIB Connected DiskDrives - Scrap or save?
Hi I'm not sure what a 9122c is. I am looking for the extention cable for the hp8660c modules part number 11672-60001
Please let me know whats happening Thank you Bob Levy
On Sunday, December 6, 2020, 7:13:29 AM EST, ulf_r_k via groups.io <ulf_r_k@...> wrote:
This not forgotten.
The 9122C was picked up today. I have the other one still in my storage area.
Shipping charges are anywhere up to €80 depending upon where
and how. It seems however that the increased e-trading because
of Covid has saturated some shipping services. I don't think it will be a good idea
to try to ship anything before january 2021.
I will get back once I have figured out a way to receive the amount needed
for shipping.
Best Regards
Ulf Kylenfall
SM6GXV
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Re: 9122 and 9122C - HPIB Connected DiskDrives - Scrap or save?
This not forgotten.
The 9122C was picked up today. I have the other one still in my storage area.
Shipping charges are anywhere up to €80 depending upon where
and how. It seems however that the increased e-trading because
of Covid has saturated some shipping services. I don't think it will be a good idea
to try to ship anything before january 2021.
I will get back once I have figured out a way to receive the amount needed
for shipping.
Best Regards
Ulf Kylenfall
SM6GXV
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Re: Weather resistant, covered Litz wire wanted.
Am 06.12.2020 um 02:43 schrieb Kuba
Ober:
There¡¯s probably some lore that perpetuates the ¡°RF is black magic¡± thing, and all sorts of myths get accepted into such lore. That¡¯s the thing about disjoint knowledge: people may say ¡°PVC is high loss¡± but they don¡¯t know what are the practical implications of it, they only may have heard it said in relation to an antenna or another ¡°incomprehensible¡± object, and the link from that bit of ¡°fact¡± to everyday life just isn¡¯t there.
There is a very nice Starlink customer terminal tear down video on YouTube (that device is a brilliant bit of engineering BTW) and a good vuunk of the comment section just goes to show that magical thinking is here to stay.
Cheers, Kuba
Polyvinylchlorid
(PVC-U)
| Allgemeine
Eigenschaften |
| Werkstoffnummer |
|
2690 |
| Dielektrischer Verlustfaktor
1 MHz |
IEC 60250 |
300 |
| Durchschlagfestigkeit |
IEC 60243-1 |
40 |
| Dicke f¨¹r Durchschlagfestigkeit |
|
0,6 |
Polypropylen
Homopolymer (PP-H)
| Allgemeine
Eigenschaften |
| Werkstoffnummer |
|
1502 |
| Dielektrischer Verlustfaktor
50 Hz |
IEC 60250 |
2,5 |
| Dielektrischer Verlustfaktor
1 MHz |
IEC 60250 |
3,5 |
| Durchschlagfestigkeit |
IEC 60243-1 |
50 |
Tabelle 18:
Zusammenfassung der Eigenschaften von PTFE, FEP und PFA
| Eigenschaften |
Spezifikationen (ASTM) |
FEP |
| Dielektrizit?tskonstante |
D 150 bei 106 Hz |
2,1 |
| Dielektrischer Verlustfaktor |
D 150 bei 103 Hz |
0,0001 |
| Dielektrischer Verlustfaktor |
D 150 bei 106 Hz |
0,0008 |
| Durchschlagsfestigkeit |
D 149 |
2000
|
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Re: 8590B power supply repair
Hi Mark,
Ok, noted.? Thanks.
Tom
toggle quoted message
Show quoted text
On 12/5/2020 4:04 PM, Mark Bielman wrote: Hi Tom,
I am not familiar w/this supply (assume it's NOT from HP) but I would have input diode rectifiers handy (single or bridge) as well as MOSFET's that drive the transformer.
Hope you have a variable AC supply for testing! Good luck.
Mark
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Re: Weather resistant, covered Litz wire wanted.
A bit like Mary Poppins: Practically perfect in every way.
-Chuck Harris
donald collie wrote:
Can anybody comment on how well Teflon weathers?
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Re: Weather resistant, covered Litz wire wanted.
Bruce : I`m trying to resonate this loop over the HF band, but it may be necessary to switch out turns with a relay etc. I plan to use the loop in its non-resonant mode, then resonate it to produce more output. Sam : Rainer has Teflon sheathed Litz wire available - nice stuff. OK on dielectric loss of PVC vs PE. Can anybody comment on how well Teflon weathers? Could you just put regular Litz wire in teflon tubing?
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Re: 8590B power supply repair
Tom,
Send me a PM and I'll send info that I have.
W3OHM
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Re: Weather resistant, covered Litz wire wanted.
Could you just put regular Litz wire in teflon tubing?
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Re: Weather resistant, covered Litz wire wanted.
There¡¯s probably some lore that perpetuates the ¡°RF is black magic¡± thing, and all sorts of myths get accepted into such lore. That¡¯s the thing about disjoint knowledge: people may say ¡°PVC is high loss¡± but they don¡¯t know what are the practical implications of it, they only may have heard it said in relation to an antenna or another ¡°incomprehensible¡± object, and the link from that bit of ¡°fact¡± to everyday life just isn¡¯t there.
There is a very nice Starlink customer terminal tear down video on YouTube (that device is a brilliant bit of engineering BTW) and a good vuunk of the comment section just goes to show that magical thinking is here to stay.
Cheers, Kuba
toggle quoted message
Show quoted text
5 dec. 2020 kl. 9:16 fm skrev Chuck Harris <cfharris@...>:
?Ordinary PVC is very, very low loss through low microwave frequencies, as is
easily demonstrated by putting a piece in your microwave oven.
Do you have a reference I can look at that shows your assertion?
-Chuck Harris
Andy ZL3AG via groups.io wrote:
Depending on the frequency, PVC's loss tangent will ruin your loop Q, so try to use
HDPE or LDPE instead.
Possible source of litz wire can be transformers used in high efficiency SMPS's, but
the ideal litz wire (wire thickness and qty of wires) changes, even across the MW band.
If you want to build a kick-arse receive loop for MW, I highly recommend the late
Graham Maynard's "Sprial loop with Q multiplier" as found in Practical Wireless - the
best loop I've ever used (feeding into a Racal RA17L).
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Re: WTB HP 8660C Module Extension Cables 11672
Hello
do you still have the extention cables .
11672-60001.
Please let me know
Thanks
Bob Levy
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Re: 8590B low sensitivity problem
Martin,
?Two things:
Check your email for an email from me.?
Be very careful when checking anything in the input circuit with an ohmmeter. Don't make any measurements where the input mixer could be subjected to DC from an ohmmeter and beware of ESD. Either one of these could damage the mixer diodes.
73,
Sam
W3OHM
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Go to https://www.tubesandmore.com/products/capacitors?filters=Brand%3DCE%20Manufacturing
They sell the CE Mfg can caps.
Dave
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I have quite a few updates.
The external monitor I had was working. Yesterday I tried my (very) old PC to boot the original hard drive that was in the scope and noticed weird things with the monitor. It went from showing BIOS to suddenly acting weird after the initial boot screen.
In any case, I was able to find another monitor and now both, the scope and the old PC, display properly. I honestly don't know what happened to the monitor because it shows some screens, but not others, however, it was originally showing the screens that no longer work. In any case, let's forget all the display issues I was having and move onto booting issues.
Here is what I've tried with the scope (remember all the boards are removed and nothing is connected to the motherboard): the bare motherboard, the original RAM, a "new" stick of RAM in both the original slot and switched to the middle slot, cable slot IDE1 and IDE2, and a different IDE cable.
Here is what I tried with my old PC: I used the XP boot CD I made for the scope in the CD-ROM and the PC booted fine.
In all cases, the scope has basically consistent results. Using power from the PC (because it has a four-pin connector) to power the CD-ROM and the IDE cable from the scope, I booted the scope. In both IDE 1 and IDE2 I got a blue screen. The normal boot sequence is: the screen shows a horizontal progress line as it boots, then it shows Microsoft Corporation in small color print, and from there, I get the blue screen (on the scope) or a Windows basic desktop with the boot software options on the PC.
If I boot the scope with no drive connected, I get a 'disk boot failure' as I do if I try the original SSD.
This tells me something is wrong with the motherboard because I tried all variations as listed above. Unfortunately I can't get the original SSD hard drive to boot in my PC. It shows the same jumbled name (S;nDirk...) as when it's in the scope.
The final results are: the CD that boots fine in the PC doesn't boot in the scope (same CD-ROM, same power source, different IDE cable, but I tried two cables.The original SSD in the scope doesn't boot in the PC; nor does a 5.25" drive I extracted an image to (but forget which image I used - whether it was from the SSD or the one from the previous owner who imaged the drive before replacing it with the SSD).
Attached are several pictures for a visual of which screens I saw.
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Re: Weather resistant, covered Litz wire wanted.
This is why I love this site!!
On Sat, Dec 5, 2020, 3:01 PM John Lyles < jtml@...> wrote: For a comparison of PVC versus PE (HDPE is just as good), the best source of dielectric loss mesurements is Von Hipples work from MIT, around WWII. Since you may not have his text book, can download the data from "Tables of Dielectric Materials" from , I think that's the Defense Technical Info Center. Google it, and Von Hipples name. Once you downloaded the PDF, look at page 116 for polyvinyl Chloride and page 153 for polyethylene. Dielectric constants for both are relatively similar. But look at loss tangent. At 1 MHz PVC is 0.016, PE is 0.0002. And you can see similar difference up to 10^7 (10 MHz) and 10^8 Hz. In RF heating (which is the effect that loss give), the loss tangent is directly related as is frequency. Electric field is a squared term. I would not recommend PVC insulation on anything that has high RF voltage in the MHz, unless you don't mind the loss and the part is cooled. Using PVC pieces as spiders for an open wire RF transmission line that is matched is probably OK, but not in a resonant circuit where the electric field rises. So it depends on the application. PVC is a very polar molecule like water, having a net dipole moment. These little dipoles are what causes the loss. Don't forget that a microwave oven at 2450 MHz has a low field strength as it is not a single resonant mode, in fact the fields are bouncing all around. When I worked for DuPont years ago, I was in the dielectric heating group. We would get chemists all the time saying "this stuff is great, I put in in my microwave oven and it only warmed in xx minutes." To which we would open the cover of our 90 Mhz WT LaRose heater with about 15 kV across the plates, and the PVC would catch on fire in 10-20 seconds. Believe me, I have done this dozens of times to prove out various hose and insulation materials in high power RF amplifiers in my workplace.
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Sam Reaves
Mike Vande Voort