Tag: hp

HP 6644A refurbishment – front panel, back protector (#P14F)

Time to finish the HP 6644A revamp!

tl;dr for the last post: Here’s where I stopped refurbishment after cleaning and replacing caps and fan:

First off, those leads stick out quite a bit at the back as well. I can’t really say which diameter I used, judging from the yellow cable lugs these were 4mm² for the power lines and 1.5mm² (red lugs) for the sense lines. Apart from not fitting the old protector, that one already has seen some damage. Probably because it is so tiny…

So: Redesign. Twice, as the first version that closely resembled the original design had really flimsy legs that suffered the very same fate. […]

18th August 2019 18th August 2019 By Bzzz In No Comment

Post #100 HP 6644A refurbishment (#P14)

Not that anybody cares, but this is actually post number 100 already. I prepared something else that failed (to be reported!), so this one has to do instead ;)

My “lab” power supply situation is ageing and often no longer up to the task, think of LEDs north of 35V or anything that takes more than one amp at voltages that cannot be provided with common computer supplies (3.3V, 5V, 12V, 19/20V) easily. So this is part one of the refresh.

I bought a HP 6644A power supply around six weeks ago off eBay, at 245€ including shipping and rack mounts via best offer. […]

23rd June 2019 20th June 2019 By Bzzz In 1 Comment

Mellanox ConnectX-3 MCX311A-XCAT 10GbE and Solaris 11.3 (WHL #42)

The heat. F*ck me.

I think post #42 deserves something nerdy. More nerdy than usual. Glad to report that I just bought something suitable – two Mellanox SFP+ cards (MCX311A-XCAT), capable of 10GbE over fibre (IEEE 802.3ae) and per DAC cables (not even sure which 802 that is – 802.3ak is Twinax as used in DAC, but thats quad-Twinax as used in CX-4 connectors, like Infiniband does). 55.00€ delivered from the Netherlands, as fast network connections are “Neuland” in Germany and therefore carry a heavy premium. Slap on some 1.5m of compatible FS.com DAC cable for another measly 17.02€ and we have 10 gigabit Ethernet between two desktop computers. […]

29th July 2018 29th July 2018 By Bzzz In 1 Comment