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Re: HP 8341B Band 3 Un Levelled

 


Check for AC ripple on the power supply rails.
Re: Transistors for the A17 voltage regulator 8642B

 

This is the problem when people insist on not quoting the original message and appropriate replies.

A little net etiquette goes a long way and reduces questions and confusion.

Glenn

On 10/29/2018 12:41 PM, Sergey Kubushyn wrote:
On Mon, 29 Oct 2018, Goran Finnberg wrote:

Sergey Kubushyn:

2N4401 is _NOT_ a transistor. It is THYRISTOR aka SCR.
Sorry, no.

The 2N4401 is an NPN transistor.

Datasheet here:

www.onsemi.com/pub_link/Collateral/2N4401-D.PDF
I think 4401 is a typo -- it is a TO-92 transistor and original post was
about 2N4101 in TO-66 package:

pdf.datasheetcatalog.com/datasheets/newjerseysemiconductor/2N4101-2N4102.pdf

There is no 2N4401 in TO-66; it is a low power general purpose transistor,
nothing special.

---
*
*? KSI@home??? KOI8 Net? < >? The impossible we do immediately.? *
*? Las Vegas?? NV, USA?? < >? Miracles require 24-hour notice.?? *
*


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Re: HP 8341B Band 3 Un Levelled

 

I didn't have this specific one but I did have a similar issue with 8340B going unleveled in Band 2 - The solution to stop the unleveling (but not to get the output back into spec) was to reload the values from the print out in the case.?

Not sure if they got corrupted, someone played with them or something else but doing that fixed the unleveled issue and allowed me to get on with tweaking the unit.

Might be worth a try.

TonyG
Re: Transistors for the A17 voltage regulator 8642B

 

On Mon, 29 Oct 2018, Goran Finnberg wrote:

Sergey Kubushyn:

2N4401 is _NOT_ a transistor. It is THYRISTOR aka SCR.
Sorry, no.

The 2N4401 is an NPN transistor.

Datasheet here:

www.onsemi.com/pub_link/Collateral/2N4401-D.PDF
I think 4401 is a typo -- it is a TO-92 transistor and original post was
about 2N4101 in TO-66 package:

pdf.datasheetcatalog.com/datasheets/newjerseysemiconductor/2N4101-2N4102.pdf

There is no 2N4401 in TO-66; it is a low power general purpose transistor,
nothing special.

---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
Re: Transistors for the A17 voltage regulator 8642B

Dale H. Cook
 

At 11:00 AM 10/29/2018, wilson2115 wrote:

I am currently testing Q10 which is 1884-0065 PRX, which is shown as 2N3670 in the manual.
Note that the 1884-0065 is not shown as identical to the 2N3670 in the HP transistor cross references, so it may be a selected 2N3670.

Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
Re: HP 8341B Band 3 Un Levelled

 

¿ªÔÆÌåÓý

Afternoon HP Group
?
????????????????????? Trying to sort our HP8341B 20GHz Sweeper but Problem with Band 3 13.5 GHz ¨C 20 GHz Un-Levelled Light is ON . Setting 0.0dBm Level on Lower Bands is OK (CW Mode) but Band 3 Levels go too ¨C13dBm to ¨C19dBm? All Voltage Rails are OK and done some Board Swaps with another Unit but not cured problem yet.... any ideas ???
?

Kind regards
Marc Christian

Telford Electronics. Old Officers Mess. Hoo Farm. Humbers Lane. Horton
Telford. Shropshire. TF6 6DJ. UK
01952 605451
www.telford-electronics.co.uk
Re: Transistors for the A17 voltage regulator 8642B

 

I had several fuses on A18 blown as a result of the misaligned connector to A17, I replaced them all. One of them was hard to get which was a 1/4 ampere fuse. I am currently reassembling A17 as the various SCR's and transistors appear. I will see if in fact power is getting to A17 from A18.
Re: HP8663A Power supply, was: Firmware difference

 

Hi Scott

Thanks for your input, But the 8663A originally has a SMPS, same PSU thats in the 8662A.
Three of the voltages, -40V, -10V and +20V go trough a linear regulator board, that I do have, and will use.

At least Mean Well is a known producer from Taiwan that's been in this businesses? for several years, so guess it will be better than the noname Chinese PSU modules.
Time will show.

Askild





On Mon, Oct 29, 2018 at 3:30 PM Scott McGrath <scott@...> wrote:
I think you are going to want better supplies than the inexpensive mean-wells SMPS,? ?HP used linear power supplies for a reason and that was there are no HF components on the DC supply rails to cause noise problems in the circuits.?


One place they deviated from that? was the 70000 series where the main chassis was a massive SMPS

Content by Scott
Typos by Siri
Re: Transistors for the A17 voltage regulator 8642B

 

I assume you have checked all the 5 fuses on the A18 board? If the fan works it means one of the negative supplies is ok (pre-regulator at least) but there are 4 other fuses

measuring on the large capacitor pins is no good because the fuses come AFTER the capacitors. you should measure the voltages at the edge of A17

this thing blows fuses sometimes even if the PSU is ok (due to strong rush in currents I think) specially if? the switch was turned on before plugging it to the outlet
note that the pre-regulator supply in this beast is always on even after turning the switch off

?
Re: Transistors for the A17 voltage regulator 8642B

 

I will have to get back on what voltages I measured, however at the time of the incident which was some time ago, I recall from memory the fan came on when I pushed the power button but all the LED's on A17 were all out and there was no display on the front. This is after I realigned the power connector. I figured I probably blew something in the regulator. I should have measured the voltages coming out of the regulator test points but I did measure the voltages out of the rectifier board and they were all fine and within tolerance

I am currently testing Q10 which is 1884-0065 PRX, which is shown as 2N3670 in the manual. I performed the same test on it as the 2N4101 with the bulb and touching the gate, it works. However my concern is the current draw when I touch the gate it rises to my set current limit of about 0.4 to 0.5 on the DC supply and when I release it goes down and the bulb glows.
Re: Transistors for the A17 voltage regulator 8642B

 

what voltages are you measuring on the 5 supply rails on the edge of A17?

remember if you decide to take the power supply out and disconnect it from the instrument (ribbon cable that goes to A5)?
you must connect the sense lines at each rail to the supply line
otherwise the voltages will be all over the place (no regulation)
Re: Transistors for the A17 voltage regulator 8642B

 

I performed a different test to check the 3 2N4101 SCR's, thanks for the correction. I powered them up with a DC supply and the load was a small bulb at 9V, when I touch the gate the SCR latches and the the bulb glows, all 3 are just fine. I attached a data sheet for these transistors which allowed me to run this test

2N4101 SCR.pdf
2N4101 SCR.pdf

Re: HP8663A Power supply, was: Firmware difference

 

I think you are going to want better supplies than the inexpensive mean-wells SMPS, HP used linear power supplies for a reason and that was there are no HF components on the DC supply rails to cause noise problems in the circuits.


One place they deviated from that was the 70000 series where the main chassis was a massive SMPS

Content by Scott
Typos by Siri
Re: Transistor Devices Dynaload DLF50-85-500

 

For anyone interested in the other going for $175 on eBay from the link above, you can make an offer below that, mine was $140 and they accepted that if your interested. Perhaps it can be had for $130 or even $120, good luck.
Re: Transistors for the A17 voltage regulator 8642B

 

He was referring to Q4,Q7,Q10,Q13 on the A17 board and I clearly remember them being thyristors
I dont remember their part numbers but 2N4101 rings a bell
one of them is different than the other 3 but they are all thyristors and are parallel to the supply rails for over voltage protection
there is another thyristor on that board which is a can shape (TO-205 perhaps) for the 50V rail

all pass transistors are mounted on the right side of the board on a big heatsink.
Re: Transistors for the A17 voltage regulator 8642B

 

Typo
2N4101 is an SCR and subject of OP.
(2N4401 is transistor and typo by Sergey)

Robert G8RPI.
Re: Transistors for the A17 voltage regulator 8642B

 

There seems to be some confusion here on just what number is being discussed.
Are we talking about a 2N4401, or a 2N4101???? The 4101 is an SCR, and the 4401 is a NPN transistor (TO-92), and I suspect one of the posts had a typo in it.
I think we should be discussing the 2N4101 here.


Daun

Daun E. Yeagley II, N8ASB

On 10/29/2018 8:34 AM, Goran Finnberg wrote:
Sergey Kubushyn:

2N4401 is _NOT_ a transistor. It is THYRISTOR aka SCR.
Sorry, no.

The 2N4401 is an NPN transistor.

Datasheet here:

www.onsemi.com/pub_link/Collateral/2N4401-D.PDF

----------------

Best regards,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: mastering@...

Learn from the mistakes of others, you can never live long enough to
make them all yourself.??? -?? John Luther

(\__/)
(='.'=)
(")_(") Nero & Smurfen:RIP
Re: HP5000A Logic Analyzer

 

This comment from the HP Memory Project is enlightening
"Even if presented as a standalone Logic Analyzer instrument, reading the HP Journal article clearly reveals that the 5000A was first of all a sophisticated digital trigger to be used with a companion oscilloscope."
Article is in October 1973 issue of the Hewlett Packard Journal.

Robert G8RPI.
Transistors for the A17 voltage regulator 8642B

 

Sergey Kubushyn:

2N4401 is _NOT_ a transistor. It is THYRISTOR aka SCR.
Sorry, no.

The 2N4401 is an NPN transistor.

Datasheet here:

www.onsemi.com/pub_link/Collateral/2N4401-D.PDF

----------------

Best regards,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: mastering@...

Learn from the mistakes of others, you can never live long enough to
make them all yourself.??? -?? John Luther

(\__/)
(='.'=)
(")_(") Nero & Smurfen:RIP
Re: Transistors for the A17 voltage regulator 8642B

 

On Sun, Oct 28, 2018 at 08:14 PM, <wilson2115@...> wrote:
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.
those are thyristors and extremely tough to break. more than likely they are not broken. forget those.

what are the symptoms? which rails are not working? there are +/- 15V, +/- 5.2V, and 50V rails
you can measure them all on the test points on the top edge of the A17 board
59361 - 59380 of 151597