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Re: VNA calibration kit to 50 GHz

 

On Fri, 12 Jul 2024 at 12:41, Marcus Gustafsson via <mankan=[email protected]> wrote:
Hi all,

I've have no idea of their quality but these are one of the cheapest I've found that still seems trustworthy.


However I've been looking at 40GHz, 2.92mm connectors and then you can get away even cheaper


Best regards
Marcus

The specifications don't make sense to me.?


VSWR of load < 1.17
VSWR of thru < 1.15
VSWR < 1.065

So what is the last VSWR? I don't see any mention of coefficients, only specs on the open (+/- 6 deg) and short (+/- 4 deg). Normally that would be quoted as some deviation from a model, but that's not stated.


--
Dr David Kirkby Ph.D
Kirkby Microwave Ltd
Email: drkirkby@...
Web:
Telephone 07910 441670 (UK) or +44 7910 441670 (international)
Registered in England and Wales, company number 08914892.?
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT
Re: How to remove the output cable of the isolator in the 8672A

 

Its a bit overkill but it may work if there is sufficient space
Re: Made one out of workshop scrap to enable the correct tightening of SMA 's

 

On 7/12/24 07:13, george edmonds via groups.io wrote:
Made one out of workshop scrap
Good going!

Did you drill that wrench handle as-is, or after heating and annealing so it drilled more easily? Or is it not a drill hole I see there?
Re: HP 8566B - Can my high voltage transformer be faulty?

 

I'll check. I know there was some CRT wiring in the "kit", just not certain if it included the multiplier. We'll find out Sunday when I can get to it.?

Dave Casey?

On Fri, Jul 12, 2024, 1:47 PM Chuck Harris via <cfharris=[email protected]> wrote:
It is mounted on the chassis, and is in the middle of the wire that
goes between the power supply board, and the anode cap of the CRT.

-Chuck Harris


On Fri, 12 Jul 2024 09:16:50 +0200 "Dave Casey" <polara413@...>
wrote:
> I'll check. Is it mounted to the chassis, or is it on a board? Which
> board?
>
> Dave Casey
>
>
Re: HP1743A scope

 

Good luck with it, Renaud. The ¡®scope is worth the effort, especially if you find the differential time / time interval measurement appealing. Let us know how it goes and ask questions!
These ¡®scope are known for bad connectors, broken soldering, defective bridge rectifiers, etc. I haven¡¯t encountered a defective hybrid nor HV multiplier in any family member yet. Also, TO-92 transistors are often broken, I suspect because the mechanical tension from inserting them with their preformed leads causes atmospheric leakage after many years. I¡¯ve encountered as much as 8 or so unrelated failures in one scope.?
Re: HP1743A scope

 

Hello Raymond,
As I said it was just given to me free so I didn't asked about it's state. Then it doesn't work, or possibly I didn't know how to get a trace, I only spent a very short time.
"All 174x-series 'scopes share many components and subsystems, so are quite repairable."
There's still the HP hybrid failed risk maybe? I will investigate when I have more time for that. I got the original paper Ins/service manual in the pocket over the scope. Nice find!
Thanks for the nice report about that little scope Raymond,
Renaud
Re: How to remove the output cable of the isolator in the 8672A

 

Made one out of workshop scrap to enable the correct tightening of SMA 's on a Marconi 2955R The hex shaft fits my toque screw driver. Cost, a bit of MIG welding.

G Edmonds
On Friday 12 July 2024 at 13:46:01 BST, Jim Ford <james.ford@...> wrote:


Erik, check Mini-Circuits for a 5/16 inch wrench with such a slot in it for the coax.? Before you attempt to make your own.? ?Seems like I saw one around here at Raytheon.? Blue anodized aluminum (aluminium for the Brits in the crowd), IIRC.? ? HTH? ? ? ?Jim Ford?


On Thu, Jul 11, 2024 at 10:40 PM, Erik Kaashoek
<erik@...> wrote:
On Thu, Jul 11, 2024 at 06:22 PM, WB2UAQ wrote:
If I remember correctly you need to remove the top, bottom and side covers.? ?Then remove the screws that hold the from panel to the side castings (go in at 45 degrees).? ?I think you can move the entire front panel forward to gain access after removing the knurled nut from the N connector.? We had a 5/16" box wrench for the SMA's that was cut open to slide over the semi-rigid coax.?
Many thanks. This is exactly the information I was (unfortunately) looking for.

Crowfoot1.JPG

Re: How to remove the output cable of the isolator in the 8672A

 

Erik, check Mini-Circuits for a 5/16 inch wrench with such a slot in it for the coax.? Before you attempt to make your own.? ?Seems like I saw one around here at Raytheon.? Blue anodized aluminum (aluminium for the Brits in the crowd), IIRC.? ? HTH? ? ? ?Jim Ford?


On Thu, Jul 11, 2024 at 10:40 PM, Erik Kaashoek
<erik@...> wrote:
On Thu, Jul 11, 2024 at 06:22 PM, WB2UAQ wrote:
If I remember correctly you need to remove the top, bottom and side covers.? ?Then remove the screws that hold the from panel to the side castings (go in at 45 degrees).? ?I think you can move the entire front panel forward to gain access after removing the knurled nut from the N connector.? We had a 5/16" box wrench for the SMA's that was cut open to slide over the semi-rigid coax.?
Many thanks. This is exactly the information I was (unfortunately) looking for.

Re: HP 8566B - Can my high voltage transformer be faulty?

 

It is mounted on the chassis, and is in the middle of the wire that
goes between the power supply board, and the anode cap of the CRT.

-Chuck Harris


On Fri, 12 Jul 2024 09:16:50 +0200 "Dave Casey" <polara413@...>
wrote:
I'll check. Is it mounted to the chassis, or is it on a board? Which
board?

Dave Casey
Re: VNA calibration kit to 50 GHz

 

Hi all,

I've have no idea of their quality but these are one of the cheapest I've found that still seems trustworthy.


However I've been looking at 40GHz, 2.92mm connectors and then you can get away even cheaper


Best regards
Marcus
Re: HP1743A scope

 

- The probe power sockets on the Tek 454 were Sealectro brand.?
- The HP 1740A is from a later era than the Tek 453/454. The contemporary Tek generation was the much lighter 465 family.
- The HP 174X family had discrete (FET) inputs, followed by an HP-specific hybrid.
- The HP 1743A is a very nice family member: The lovely red LED display does not just show *the* delay time ("time base B")
but differential delay (dual delayed sweep!) *and* does not do it the conventional analog way (voltage difference,
like 7B85/7B80 in the Tek 7000 family) but contains a digital counter circuit, resulting in much higher resolution and accuracy,
see HP Journal 1977-12.
All 174x-series 'scopes share many components and subsystems, so are quite repairable.

Raymond
Re: HP1743A scope

 

The first scope I used at work was a 1740A - similar but with a vernier dial rather than the LED display for the timebase delay.?
My boss was a big HP fan and probably inspired my own enthusiasm for their kit.
Some years later I got a secondhand 1725A (replacing a previous 180A) and it served me for many years. Solid equipment (in more ways than one .. fortunately I didn't have to move it much).

I think it will have some exotic HP hybrids for input stages. If those are broken it will be a problem. But worth repairing if you still enjoy using an analog scope.

I agree with Nigel that the Tek connectors look like Lemo. That half-round polarisation is characteristic. However all the ones I've encountered have smaller pins. You might also check Fischer.
Re: HP1743A scope

 

On Fri, Jul 12, 2024 at 10:44 AM, nigel adams wrote:
I think the power plugs on the Tek scope may be a Lemo type¡­
Thanks Nigel, yes I suppose so too. I had a look at the Lemo site. There's a tool to find your particular kind of plug. You select the number of pins and plenty of parameters which I did and the thing told me I now only had too look at 68000 models...
That's only for fun because the only active probe I have is a Tek P6202A and I built a little psu for it to avoid using each time? the 7704A as psu. I only wonder which probes were supposed to be used with the 454. Then I'm pretty sure some kind fellow here will tell me that!
Renaud
VNA calibration kit to 50 GHz

 

Making good quantitative measurement using a vna requires a decent calibration kit. So i'm just wondering the most cost effective way of getting hold of one which works up to 50 GHz. Sure, you can buy from Keysight a beautiful wooden box containing something which looks like a few coaxial connectors for $12,000. Or, you can hack and solder up some coaxial connectors yourself. Between these extremes you might buy something from ebay or another websites which may offer good second hand kits, or possible fake ones. I'd be interested to learn from others the recommended ways for getting a decent calibration kit.
?
many thanks, Neil? ?
Re: HP1743A scope

 

¿ªÔÆÌåÓý

I think the power plugs on the Tek scope may be a Lemo type¡­

Hope it helps

Regards

Nigel

?

From: [email protected] <[email protected]> On Behalf Of Renaud F5ZR via groups.io
Sent: Friday, July 12, 2024 9:11 AM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] HP1743A scope

?

Hi,
I was just given this (rather dirty, but what does one say about the given horse?) cutie:



Considered "portable" (if you don't mind 15 kG)
Any comments welcome as usual.

By the way I also have that similar Tek which is I believe from the same era:

Which is indeed portable. But what are those probe power plugs? Different of course from those of my 7704!
I will probably post that too on the g.ioTek parallel universe.
Renaud
HP1743A scope

 

Hi,
I was just given this (rather dirty, but what does one say about the given horse?) cutie:



Considered "portable" (if you don't mind 15 kG)
Any comments welcome as usual.

By the way I also have that similar Tek which is I believe from the same era:

Which is indeed portable. But what are those probe power plugs? Different of course from those of my 7704!
I will probably post that too on the g.ioTek parallel universe.
Renaud
Re: HP 8566B - Can my high voltage transformer be faulty?

 

I'll check. Is it mounted to the chassis, or is it on a board? Which board?

Dave Casey

On Fri, Jul 12, 2024, 12:40 AM saevar via <saevartj=[email protected]> wrote:
Hi Dave Casey,

The part that seems to be broken is: 0960-0383 VARO MH920E03 Do you have one of those in a good shape?

Re: How to remove the output cable of the isolator in the 8672A

 

On Thu, Jul 11, 2024 at 06:22 PM, WB2UAQ wrote:
If I remember correctly you need to remove the top, bottom and side covers.? ?Then remove the screws that hold the from panel to the side castings (go in at 45 degrees).? ?I think you can move the entire front panel forward to gain access after removing the knurled nut from the N connector.? We had a 5/16" box wrench for the SMA's that was cut open to slide over the semi-rigid coax.?
Many thanks. This is exactly the information I was (unfortunately) looking for.
Re: Bubble Memory Reseed

 

On thinking some more on this, I'd guess that the necessary info in the battery-backed memory would be the "bad bit" map of the particular bubble unit in the machine, so you can tell which ones to use or not. This could be figured out during the "re-formatting" whatever function, then stored for reference. Anyway, whatever it all does, that should get things working again.

Ed
Re: Bubble Memory Reseed

 

I have a 3561A, and have never encountered need for any kind of special module, but I did have to do something in the menu/setup/diagnostic controls. There is a re-something function built into the machine, to basically restart/re-format the bubble memory from scratch. As I recall, it was because the backup battery (for the processor - not for the bubble memory function per se) was dead, so you had to totally reboot everything. I think the battery-backed data has info on running the bubble memory, so if it's lost, you have to start over. The manual definitely has the answer, but not necessarily in an obvious way. If I think of anything else on this, I'll report on it. Good luck.

Ed
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