Farnell currently have suitable fans on offer at a pretty good
price.
I just bought 6 to use in my collection of 66xx system power
supplies currently being slowly cleaned up and fixed.
Farnell part number 1545836
Michael Kellett,
MK Electronics Ltd.,
On 18/02/2022 09:20, Christopher Tucker
via groups.io wrote:
toggle quoted message
Show quoted text
I have replaced noisy 115VAC fans with 12VDC Noiseblocker
Black Silent Pro PL-2 fans from Germany. For my 140S, I
bought a 120mm but they have other sizes. There is a retailer in
Ireland that ships to the EU rather easily:
The fan is thinner than the original which made
installation a bit easier. The caveat is you will need to create
a small board to convert the 115VAC to 12VDC using four 1N4007,
four 1/2W resistors to halve the voltage twice 110 -> 55
-> 27.5 to meet the upper threshold of the 7812, and a 1uF
35V electrolytic filter capacitor. The fan is so silent one can
hear the subtle buzzing of the transformer. I opted to construct
two aluminum 90-degree bends from the upper pair of
fan-transistor plane bolts to attach the circuitboard parallel
such that it was under the level of the cover.
I also had to make some custom bolts from a longer
piece of M4 from a Bauhaus to attach the cooling planes for the
four power transistors - also with some M4 washers, etc because
of the difference between SAE and metric. The result is very
nice but I had to run the fan from an external battery while
testing/building the conversion circuit to keep the transistors
cool.
You can get the datasheet from here:
Christopher
|
Re: HP8903B - Plotting from HP-IB
Thanks Dave, for the info - I'll have to take a look into VISA for the ProLogix - I moved from a Prologix to an 82357 and ended up with an NI GPIB-ENET/1000 - It'd be good to have the possibility of using the Prologix as well.
Attilio - When you get the Keysight IO Libraries Suite installed you may still need to configure the instrument to use address 14 or modify the settings used by Pete's software - In VEE there is a thing called Instrument Manager and you can do that - Pete has information on his website about it.
Good luck with it.
TonyG
|
I had the exact same problem with my 8970B
Took the old fan out and placed it in the bin - no need to try to make it quiet. Even from new it is to noisy
In Europe it is easy to get hold of Noctua fan's, they are silent
The 8970B has the power supply near? the fan, so I took the +15V rail and added a small "Fan Conrtroller" to make in even more silent
I never use my equipment in higher than 25°C ambient
The sensor for the fan controller was placed at the heat sink, which I found was the hottest place
Been running for years now
The original fan was a?
ETRI - 99XW 0182 000
Which I replaced with a?
Noctua - NF-A9 PWM (I did not use the PWM signal)
The fan controller is just a LM2940T regulator with a resistor and a thermistor
/Hans
? ? ??
|
The thermal converter is used to adjust the amplitude flatness of the 3325A for sine waves. This is done by comparing the RMS values of the output at two voltage settings (3Vp-p, 10Vp-p) at 1kHz, to the values at 10MHz, 16MHz and 20MHz. The 3325A specification for flatness (at these settings) is roughly +-3.5%, which is not terribly accurate or hard to measure.
One way, for example, is to use a good digital scope (DSO). A typical absolute vertical amplitude accuracy specification of a DSO with an 8-bit ADC is about 2%. Note, however, that you want relative accuracy (i.e., the vertical flatness of the scope in the range of 1kHz to 20MHz) which for a typical 100MHz DSO would usually be quite better than 2%, and enough for this application. If your DSO has higher bandwidth you can operate it in high resolution mode which would be even better.
Another option is to use an HP 3403C which is much more easy to find than the 11050A, and is plenty accurate enough for this application.
|
In general the fans can be taken apart and new light grease/oil added. Its tricky and all I can say is watch out for the little c clip to fly out when you take one apart. Sometimes you can even find replacement bearings. If its a sleeve bearing all you can do is grease it and hope. Generally tends to work. Regards Paul WB8TSL
|
Re: HP8903B - Plotting from HP-IB
Thanks Tony, thanks Dave,
to avoid troubles too much I bought an HP82357B interface GPIB <-> USB with the hope that it will work with keysight software (VEE, I / O, VISA, etc.). I am waiting to receive it.
-- Cheers
? ? Attilio
|
Re: Selling experience, sorry OT again
I have no experience with ebay Australia but in France very common to accept only a French bank chèque sent via post.
Many French sellers restrict auctions to French only and shun PayPal.
I have completed many ebay.fr purchase over years pay via check, in � no PayPal no fees!
PayPal and ebay fees are ever more complex and increasing, without VAT we would ask at least 10% extra from the buyer to cover,the fees and then add VAT.
Finally the incredible Brexit international shipping and new EU VAT led us to never ship or buy anything from UK, as the extra costs and government paperwork is not working the cost or wasted time.
We ask our UK customers to arrange and pay for shipping, and pick-up at our USA location, INCOTERM EXW.
Bon journée
Jon
|
To calibrate the 3325A, the thermal converter P / N 11050A is required, I ask if you are aware of an alternative method for this calibration step, which is impractical even if you manage to find the thermal converter 0853-0001 from Best Productis.
|
Hi Marc,
I would try a 220 volt type of fan. I did that on a number of Tektronix and HP equipment with very good results. There is still a good amount of airflow which would be ample sufficient for the 8970. You wouldn't use it at ambient temperatures beyond 40°C, would you?
cheers
Martin
|
Re: Selling experience, sorry OT again
On Thu, 17 Feb 2022 at 10:35, Froggie the Gremlin < jonpaul@...> wrote: PayPal fees for FX are incredibly high, 3..5% worst foreign currency exchange rate, plus fees, etc.
You always have the option to dump epay all together and simply sell on your own website, our firm has done so since 1995, and never sell on epay.
I do that - see for example?
However, eBay waa? 1) Another outlet for selling? 2) A way to drive customers to our website. Some people would see the company name and Google it, then realise it was cheaper to but direct, rather than through eBay. ?
For epay, What about payment via bank transfer? Physical paper bank check? Still.aloowed?
Not to my knowledge outside ebay.au (Australia), where there are specific Australian laws that meant eBay could not deny people the option of bank transfer. ?eBay may have found a way around that.?
If it was not for the fact that I believe that it would raise suspicions as a ?company, I would be tempted to look at accepting bitcoin. Nano is an interesting cryptocurrency. I have never used it, but there are no fees and according to Wikipedia, transactions are confirmed in under 1 second. These all rely on you trusting the person that you are dealing with. There would be a small fee (< 0.5%) to convert the crypto to USD or whatever one wants.
Jon
Dave
-- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
|
Potentiometer for HP5315 / 5316 counters : 2100-3719
Folks,
As part of a 5316A restoration project, I am looking for the "gate time" potentiometer which is used in the 5315 and 5316 counters.
It is a PCB-mounted 470K potentiometer with a CCW switch. The part-number is 2100-3719.
If anybody has a spare, I'd be most happy to pay a reasonable price + shipping !
Thanks,
Joel Setton
|
Re: HP8903B - Plotting from HP-IB
Re:-
From: Tony
Goodhew
Date: Thu, 17 Feb 2022 17:30:00 PST
From memory, all of Pete's software is VEE based so it expects a
VISA supported GPIB adapter.
The Prologix is a great little adapter but isn't VISA supported, I
think you'll need to get a HPAK or NI one to get it to work.
TonyG?
Depending on your OS etc, there are VISA implementations that
will support the Prologix (and clones with a little work.)
But, there are differences between (for example) NI's VISA, and
HPAK's VISA.? That, and it is impractical to bad, to have more
than one version of the VISA architecture installed on any one
PC.?? As we found to our cost and frustration at work.
It is a shame that the respective installers do not check for a
pre-existing install of others, or even an earlier version from
the same stable.
VISA is a good system, but it is bloated and can become very
unstable under mismatch situations, even to the extent of taking
down the OS!
73.
Dave G8KBV
--
Created on and sent from a Unix like PC running and using free and open source software:
|
I am facing similar task to quiet by HP5345A counter, and that is
very loud beast. Mouser has very wide selection of 115V fans where
I am just now selecting proper one. In Europe you can also try
TME.eu, they also have some 115V fans on stock.
Vladimir
toggle quoted message
Show quoted text
I
don’t have the 8970B schematic in front of me, but I’d guess
that if there is a 115VAC? fan,
it is connect across half of the 230 VAC wired primary of
the power transformer.
?
As
for reducing the noise, I have on other HP boxes put a power
resistor in series with the fan to reduce the supply
voltage. I don’t recall the value I used but the fan
nameplate should tell you the current it draws at 115, and
you can calculate a rough guess as to the resistor value and
power rating. As the HP boxes are designed with the idea of
being stuffed in a rack with other instruments also adding
heat, and allowing for the air filter to be somewhat clogged
with dust, half speed will still move plenty of air assuming
you are not operating under those conditions. That should
substantially reduce the noise, but the squeaking will
probably require some sort of attention. Some light oil
might be sufficient to determine if the bearings just are
dry. Your decision on what to do at that point.
?
?
I have an older HP 8970B which is however
in good condition. Just one thing is annoying, the fan is very
noisy and makes a loud squeaking noise. I guess the bearing
has become bad.
As this fan is 115V (even though the insrument is used with
230V) it's not that easy to get such a fan replacement in
Europe. Has anyone some advice how to get the fan quiet? Some
oil at the right position? So far I did't tear down the fan as
I don't want to berak it...
|
I have replaced noisy 115VAC fans with 12VDC Noiseblocker Black Silent Pro PL-2 fans from Germany. For my 140S, I bought a 120mm but they have other sizes. There is a retailer in Ireland that ships to the EU rather easily:
The fan is thinner than the original which made installation a bit easier. The caveat is you will need to create a small board to convert the 115VAC to 12VDC using four 1N4007, four 1/2W resistors to halve the voltage twice 110 -> 55 -> 27.5 to meet the upper threshold of the 7812, and a 1uF 35V electrolytic filter capacitor. The fan is so silent one can hear the subtle buzzing of the transformer. I opted to construct two aluminum 90-degree bends from the upper pair of fan-transistor plane bolts to attach the circuitboard parallel such that it was under the level of the cover.
I also had to make some custom bolts from a longer piece of M4 from a Bauhaus to attach the cooling planes for the four power transistors - also with some M4 washers, etc because of the difference between SAE and metric. The result is very nice but I had to run the fan from an external battery while testing/building the conversion circuit to keep the transistors cool.
You can get the datasheet from here:
Christopher
|
I don’t have the 8970B schematic in front of me, but I’d guess that if there is a 115VAC? fan, it is connect across half of the 230 VAC wired primary of the power transformer. ? As for reducing the noise, I have on other HP boxes put a power resistor in series with the fan to reduce the supply voltage. I don’t recall the value I used but the fan nameplate should tell you the current it draws at 115, and you can calculate a rough guess as to the resistor value and power rating. As the HP boxes are designed with the idea of being stuffed in a rack with other instruments also adding heat, and allowing for the air filter to be somewhat clogged with dust, half speed will still move plenty of air assuming you are not operating under those conditions. That should substantially reduce the noise, but the squeaking will probably require some sort of attention. Some light oil might be sufficient to determine if the bearings just are dry. Your decision on what to do at that point. ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Marc73
Sent: Friday, February 18, 2022 1:03 AM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] HP 8970B noisy fan? I have an older HP 8970B which is however in good condition. Just one thing is annoying, the fan is very noisy and makes a loud squeaking noise. I guess the bearing has become bad.
As this fan is 115V (even though the insrument is used with 230V) it's not that easy to get such a fan replacement in Europe. Has anyone some advice how to get the fan quiet? Some oil at the right position? So far I did't tear down the fan as I don't want to berak it...
|
Re: HP 8970B calibration / account for loss during calibration
When you do the cal, you should have the pad in the system, that is, the source drives the pad, then to the 8970 input. You will use the ENR values you have for the source. Your DUT will go between the source and the pad after you perform the cal, and you should get correct values. ? Since you corrected for the pad with your R&S test, I would expect you would get good results if you corrected for the pad both during cal and the DUT measurement, but that is a more work than needed. The cal process corrects for all the losses or gains in the signal path so that when you measure your DUT, that is already taken into account. The NFA does all the work. ? Again, SP 34 should not be needed. ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Marc73
Sent: Friday, February 18, 2022 12:58 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8970B calibration / account for loss during calibration #141-66513? Hi thanks for your reply. Of course I would like to measure 75Ohm devices. So I'd have to enter the thrue ENR of the noise source in 75Ohm system inluding the matching pad and do calibration. Afterwards wehn I do the measurements I don't have to account for the matching pad as well? The it would be very easy. BTW the 75Ohm noise source has an ENR is around 7,5dB. (I have the whole table between 50MHz and 1GHz in 50MHz steps)
I used to these measurements with an R&S FSU8 + FSK-30 option and there in included the loss of the matching pad during cal and measurement and I got correct results, that's why I wonder right now with the 8970B.
|
I have an older HP 8970B which is however in good condition. Just one thing is annoying, the fan is very noisy and makes a loud squeaking noise. I guess the bearing has become bad.
As this fan is 115V (even though the insrument is used with 230V) it's not that easy to get such a fan replacement in Europe. Has anyone some advice how to get the fan quiet? Some oil at the right position? So far I did't tear down the fan as I don't want to berak it...
|
Re: HP 8970B calibration / account for loss during calibration
Hi thanks for your reply. Of course I would like to measure 75Ohm devices. So I'd have to enter the thrue ENR of the noise source in 75Ohm system inluding the matching pad and do calibration. Afterwards wehn I do the measurements I don't have to account for the matching pad as well? The it would be very easy. BTW the 75Ohm noise source has an ENR is around 7,5dB. (I have the whole table between 50MHz and 1GHz in 50MHz steps)
I used to these measurements with an R&S FSU8 + FSK-30 option and there in included the loss of the matching pad during cal and measurement and I got correct results, that's why I wonder right now with the 8970B.
|
Re: Agilent 44xx ESG RF Generator question
I really appreciate all of the feedback!
Looking through HP/Agilent offerings it appears the 8846A may be the most reasonably priced / not ancient and needing repair model which does phase continuous sweeps I could find.? Anyone have one in good shape they are looking to part with for a reasonable price?
Thank you!
Howard Hoyt / WA4PSC
|
Re: 8350B *restoration adventure?*
Hello Ruben, ? for your question, you have to think about the main purpose of this purchase; did you intend to buy a plugin and what frequency range, or just to repair and resell? If it's to resell (without a plugin), I don't think the effort is worth it. If you really intended to buy a plugin, then you have several choices, you buy a new 8350B with the plugin included and sell the one you have, or you buy a plugin and repair with or without modification, the 8350B. ? You say that the transformer is unrepairable mainly because of corrosion, because the burnt wires are replaceable. So, if this is really the case, you will have to modify the 8350B to insert the 8566 transformer, or find a really compatible or original transformer for the 8350B. ? By chance, today, in exchange of a piece of equipment I was not using, I received an 8350B and an 83595A module.? The 8350B has several problems so part of the front panel is not working, and the 83595A needs to be checked and adjusted completely. So, like you, I will work on restoring an 8350B...however the problems are less severe. ? Whatever you decide, I wish you the best of luck. ? -Yves ? ? Hello
Thanks for the idea Yves, I thought that at first, but the original transformer is totally burned and has 4 windings in dead short between them. Also the varnish, wax paper layers and corrosion of the iron core makes the rewind task imposible. That was the reason to buy another transformer. The wrong transformer :D
Today I did supplies adjustments, all need tuning and the -40 was the only one that I couldn't adjust due to the lack of 40 millivolts,?I suppose that due to the imperfection of the connections or tiny differences on input voltages. The built-in test still says power supplies are ok (no error 004). Also adjust the 10 volt DAC reference.?
?- Current draw on the 20-0-20 secondary (which feed both 5 volt rails, 5VA and 5VB) is 4.3 at start and then 3.8 A continuous.?
?- Consumption on the rest of the rails are under 0.5 amp, probably due to the lack of plugin.
Now I feel discouraged... don't know if spend money in a plugin or abandon project
If anyone has an idea or advice, I'm open?
To be continued...
Ruben
|
Attilio
Froggie the Gremlin
Martin
Dr. David Kirkby, Kirkby Microwave Ltd
Christopher Tucker
