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Transistors for the A17 voltage regulator 8642B

 

My question concerns the 2N4101 PRX TO-66 transistors in which 3 have been blown open. . The part number and package appear correct other than being a different brand, I believe this should work.. And below if your curious about my findings so far. Below is additional information if your interested

Here is my findings so far from a misaligned power connector from the rectifier board to the regulator board, causing the regulator board to stop working and smoke smoke to come out.

here is the suspect transistors I found so far are as noted on the schematics I studied for A17 which you can see in the attachment
U10 1884-0065 PRX (Located just right of connector J2)
U7?? 2N4101 PRX (Located directly above C15)
U13 2N4101 PRX (Located just right of U7)
U4?? 2N4101 PRX (Located beside C15)

I checked other various transistors in circuit with a multimeter diode test feature for shorts or if open in circuit, they appear to be fine.

8642B A17.jpg

Good voltage cal lab in SW Ohio?

 

I'm looking for a lab in southwest Ohio that can provide a trustworthy with-data cal of an HP-3456A.? I'd rather drop off and pick up than ship the unit.

Any recommendations?

Thanks,
John
Re: Transistor Devices Dynaload DLF50-85-500

 

Sounds like a winner, thanks
Re: Transistor Devices Dynaload DLF50-85-500

 

I am looking at a DC electronic load and have come upon a
Transistor Devices Dynaload DLF50-85-500, does anyone have
experience or thoughts on this?
I've had a Transistor Devices 1 kW e-load that I bought used around 20 years
ago. It gets quite a bit of use, often at or near its rated limit. I have
only ever had one failure, and it was an easy fix - a shorted high-current
transistor. The current shunt and metering are very accurate, it's easy to
operate, built well, etc.. I can't say anything bad about it.

--- Jeff WN3A
Re: Transistor Devices Dynaload DLF50-85-500

 

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I have a pair of the RBL488 800 watt version of these. They Just Work.?

On Oct 28, 2018, at 19:31, wilson2115@... wrote:

Thanks, of what I am looking at. The seller has 2 of these for sale.

Re: Transistor Devices Dynaload DLF50-85-500

 

Thanks, of what I am looking at. The seller has 2 of these for sale.
Re: Transistor Devices Dynaload DLF50-85-500

 

I have used several of the Transistor Devices DLA, DLF series loads, and I have a small one I acquired. Documents should be available from them or from whomever has purchased them. Most of the ones I have used were bus controlled with only power on, loads toggled in or out on the front panel. They are very sensitive to over voltage conditions. If it is a full rack width then you can have up to 8 separate loads and a control card inside, gpib card will be across the back inside. The model no. indicates voltage limits and current limits. The ones I used were 1500 and 3000 amps with multiple voltage limits. They were also 75, 125, and 200A loads - paralleled as needed.
Don Bitters
Re: Transistor Devices Dynaload DLF50-85-500

 


I'm not familiar with this model, but I used to use Transistor Devices loads and power supplies while I worked in a cal lab at a Navy base years ago. ?Transistor Devices loads were always pretty rugged instruments; I don't remember ever having to repair one.
I wouldn't have any issues buying a TDI load if I were looking for one.

Cheers,
Dave M

+++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++

wilson2115@...
2:19pm???

I am looking at a DC electronic load and have come upon a Transistor Devices Dynaload DLF50-85-500, does anyone have experience or thoughts on this?
Re: HP 8643A IO board fault

tmillermdems
 

?
Well played. I repaired a 8644B that was dead above 1030 MHz. It was a bad SPDT microwave Gas switch chip on the doubler module. HP used a lot of these chips (AS002M2-12) that are still available. I see a lot of these switches fail with a lot of loss. The module passes the signal straight through below 1030 MHz then switches in the doubler above that frequency. The same circuit is used in the 8657B generator doubler module.
?
Source here:
?
?
?
?
?

----- Original Message -----
From: Siggi
Sent: Sunday, October 28, 2018 3:30 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8643A IO board fault

On Sun, Oct 28, 2018 at 13:51 Sigur?ur ?sgeirsson <siggi@...> wrote:
On Sun, 28 Oct 2018 at 13:12 tmillermdems <tmiller11147@...> wrote:
Ok, that is good. I find them to be very useful for these kinds of problems. Also, you might try unplugging modules as you monitor the current. Something is dragging it down.

Maybe not - I don't find anything getting hot. However, the -15V rail is MIA from the near end of R41, which has gone open. Dead short to ground on the -15V rail, I guess that's my problem :). It's going to be those axial tantalum caps C46/C47 I bet.
All the analog MUXes use the -15 rail, so if it's out that'd throw the diagnostics for a real spin.

It was C29, a .22uF 35V SMD tantalum capacitor. All better now, though I need to order a suitable replacement.

So I guess nothing too unusual here. The original fault was a shorted tantalum in one of the RF modules. After that I needed to recap the PSU, then back to a tantalum...
Re: HP5000A Logic Analyzer

 

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It¡¯s basically a 64-bit clocked input shift register with a latching output register connected to the display. The ¡°clocked¡± aspect is important: the analyzer is useless without a data clock. The registers can be split into two 32-bit ones (A and B separate) and can be acquired separately. The result of AND, OR and XOR between A and B can be displayed as well. Triggering is fairly flexible, with up to 64 bits of pretrigger data available, with clock delay counter, word delay counter (when the WORD input is used), and a hold-off control like in a scope.

As long as you have a clock available, and are interested in visualizing 32-64 bits of serial data, it¡¯ll be of some use. The clock requirement precludes use for e.g. NRZ signals. For all asynchronous or isochronous codes, a clock recovery circuit needs to be available. Synchronous clocked signals can be used directly.

Cheers, Kuba

PS. Looking up RZ and NRZ got me to learn about Kees Schouhamer Immink. If you don¡¯t know who he is, it¡¯s worth reading :)

28 okt. 2018 kl. 15:23 skrev Jeff Kruth via Groups.Io <kmec@...>:

In digging in my storage building, I ran across this little HP box, 5000A logic analyzer. I have read the description in the 1975 catalog, so have an idea of what it does/can do. The X-OR function looks intriguing from a SS demonstration setup perspective.

Anyone know much about this thingy? Or have used one, have comments?

Thanks in advance!

BR
Jeff Kruth
WA3ZKR
Re: Transistor Devices Dynaload DLF50-85-500

 

see?
I believe this is a dual channel 85 volt 500 watt unit. hese were overbuilt almost to mil spec.

On Sun, Oct 28, 2018 at 2:19 PM <wilson2115@...> wrote:
I am looking at a DC electronic load and have come upon a Transistor Devices Dynaload DLF50-85-500, does anyone have experience or thoughts on this?

Re: Transistor Devices Dynaload DLF50-85-500

 

TDI Dynaloads are great products. Manuals are available. I have a couple of them a 150W and a 1KW units and they are pretty bullet proof.

--
Sam Reaves
ARS W3OHM
Owner and Moderator of:
LeCroy_Owners_Group on Yahoo! Groups
LeCroy Owners Group on Groups.io (backup group)
Re: HP 8643A IO board fault

 

On Sun, Oct 28, 2018 at 13:51 Sigur?ur ?sgeirsson <siggi@...> wrote:
On Sun, 28 Oct 2018 at 13:12 tmillermdems <tmiller11147@...> wrote:
Ok, that is good. I find them to be very useful for these kinds of problems. Also, you might try unplugging modules as you monitor the current. Something is dragging it down.

Maybe not - I don't find anything getting hot. However, the -15V rail is MIA from the near end of R41, which has gone open. Dead short to ground on the -15V rail, I guess that's my problem :). It's going to be those axial tantalum caps C46/C47 I bet.
All the analog MUXes use the -15 rail, so if it's out that'd throw the diagnostics for a real spin.

It was C29, a .22uF 35V SMD tantalum capacitor. All better now, though I need to order a suitable replacement.

So I guess nothing too unusual here. The original fault was a shorted tantalum in one of the RF modules. After that I needed to recap the PSU, then back to a tantalum...
Re: HP5000A Logic Analyzer

 

In digging in my storage building, I ran across this little HP box, 5000A logic analyzer. I have read the description in the 1975 catalog, so have an idea of what it does/can do. The X-OR function looks intriguing from a SS demonstration setup perspective.

Anyone know much about this thingy? Or have used one, have comments?

Thanks in advance!

BR
Jeff Kruth
WA3ZKR
Transistor Devices Dynaload DLF50-85-500

 

I am looking at a DC electronic load and have come upon a Transistor Devices Dynaload DLF50-85-500, does anyone have experience or thoughts on this?
Re: HP 8643A IO board fault

 

On Sun, 28 Oct 2018 at 13:12 tmillermdems <tmiller11147@...> wrote:
Ok, that is good. I find them to be very useful for these kinds of problems. Also, you might try unplugging modules as you monitor the current. Something is dragging it down.

Maybe not - I don't find anything getting hot. However, the -15V rail is MIA from the near end of R41, which has gone open. Dead short to ground on the -15V rail, I guess that's my problem :). It's going to be those axial tantalum caps C46/C47 I bet.
All the analog MUXes use the -15 rail, so if it's out that'd throw the diagnostics for a real spin.
Re: HP 8643A IO board fault

tmillermdems
 

?
Ok, that is good. I find them to be very useful for these kinds of problems. Also, you might try unplugging modules as you monitor the current. Something is dragging it down.
?
I live in Forest Hill, Maryland, USA. A good bit south of you. I have been to Montreal quite a few years ago. Quite a beautiful place I might say.
?
Good luck, I like the 8643, 4 series generators. it would be nice to know more about reading all the test? points (mux readings) for these units.
?
Later,
Tom

----- Original Message -----
From: Siggi
Sent: Sunday, October 28, 2018 12:49 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8643A IO board fault

Hey Tom,

thanks for your kind offer, but I think I can snarf one from work. To answer your question, though, I'm in the frozen tundra of Montreal, Quebec. Are you nearby?

Siggi

On Sun, 28 Oct 2018 at 12:01 tmillermdems <tmiller11147@...> wrote:
Hi Siggi,
Where are you located?? I?have an IR camera.
?
Regards
Re: HP 8643A IO board fault

 

On Sun, 28 Oct 2018 at 11:51 Sigur?ur ?sgeirsson <siggi@...> wrote:
The instrument checks all point the same way, and I've isolated this as far as the built-in diagnostics will take it.

I forgot to mention that I have two LED error indicators lit on the IO board, looks like they're designated LED_BUS(5) and LED_BUS(6). I haven't seen any mention of those in the service manual, so I don't know what they're trying to tell me - alas.
Re: HP 8643A IO board fault

 

Hey Tom,

thanks for your kind offer, but I think I can snarf one from work. To answer your question, though, I'm in the frozen tundra of Montreal, Quebec. Are you nearby?

Siggi

On Sun, 28 Oct 2018 at 12:01 tmillermdems <tmiller11147@...> wrote:
Hi Siggi,
Where are you located?? I?have an IR camera.
?
Regards
Re: HP 8657D signal Generator

 

¿ªÔÆÌåÓý

I have an 8657B and it's great so I would say go for it, at that price you can't go far wrong. Let me know if you don't want it and I'll be down to collect it like a shot - mother-in-law lives in Paignton so no difficulty collecting!

Adrian


On 10/28/2018 12:44 PM, KEN WRIGHT via Groups.Io wrote:

Dear All.
I have just seen the following HP Signal Generator for sale in the UK at a very reasonable price:
HP 8657D TT/4 DQPSK Signal Generator. Would this item be a suitable replacement for my faulty HP 8656A??

Regards.

Ken Wright
59381 - 59400 of 151590