HP 105B battery - active part of filtering or not? - Page 1
Forum section: electronics / repair

author: tkamiya
author_rank: Super Contributor
timestamp: February 11, 2020, 12:15:16 pm
content: I'm getting HP-105B Crystal Oscillator Standard today. One of the first thing I'm going to do is to evaluate internal batteries. Supposedly, they are 20 Nicad C cells. I'm sure they are bad. Replacing them is an obvious solution, but here's a question.Can I leave it out? I've looked at the circuit diagram. It didn't look like it is taking an active role in filtering mains sourced power. But I also saw some where, it IS part of the filtering circuit. Which is true? I'd rather leave them out because everything is UPS backed up in my lab. But if it is going to affect phase noise, etc, due to remaining ripples, then I need that in.Thanks as always.Taka

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 11, 2020, 04:39:01 pm
content: No, it is not part of the filtering. Other than "just because" I don't think that there is a real reason to justify having the batteries installed; while I have two of these, I don't actively use them since it is far easier - and more accurate - just to feed everything with a GPS source and distribution amps. And those are backed up with a true-sine UPS which is I would feel is the route to take if you *did* want to use the 105B as a reference. Still, though, one of them *does* sit right there in my equipment rack powered up (completely sans batteries) and looking cool.Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 11, 2020, 04:55:28 pm
content: Great! Thank you.I really did not want to replace the batteries as it'll be just one more thing to replace. I have a 1KVA (I know it's too big) true sine wave rack UPS dedicated for time references only. I wanted this for its short term stability. Usually, I use GPSDO and as backup, Rubidium.Rack type UPS are very cheap on used market. I just replace the batteries and they usually work. Great and durable backup solution.

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 11, 2020, 06:29:23 pm
content: Enjoy! And, I would disagree on the UPS size - to me, that is about right or even a little larger. If you are going rack mount then that is on the smaller end of the spectrum and, if you're going to the expense and hassle of a UPS, you might as well go ahead and get one that will have the capacity to run what you want for more than a couple of hours. Also important is to go with a quality unit that is actually designed for long run times and has a reasonable smooth output waveform. While old test gear is quite resilient, it was *not* designed to cope with the God-awful stepped sine output from a cheap (as in quality) UPS, and especially not precision metrology equipment. Of course, I pretty much just have mine running to keep the batteries charged - if the power *does* go out, the SpectraCom 8195A I use comes back up to a stable (and accurate enough for me) lock pretty fast. While I'verun enthusiasticallyslipped fairly far down the rabbit hole of volt-nuttery, I've mostly resisted the dark calling of the time-nuttery temptation. Well, not according to the scary number of pieces of equipment that I have to measure frequency - I just don't have a come-apart if I'm off a few PPB.Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 11, 2020, 07:05:31 pm
content: Well.... I have more than one UPS. 3KVA, 2KVA, 2 x 1.5KVA, 1KVA. I had to pull two 30A circuit from breaker panel just for these UPSes. They all run less than 30%. Time standard one is 10% load. I am getting rid of consumer versions as they break more than just the battery. (only a few 1.5KVA units left now) They are sine wave type but looking at it inside, ratings are very optimistic on top of the game they play with watts and VA.I have two Spectracom 8195A. They are backup of backup, in case volcano erupts and earth splits apart. I had such a good deal on them, I couldn't refuse. I know what you mean by PPB. That's where everything starts to become a bit hairy! I go on emotional roller-coaster on that. (go get my MEDS!)...and I'm not kidding on this one. If time-nuttery calling get too loud for you, I'll be glad to keep some of the stuff just so I can help you out.

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 11, 2020, 07:42:32 pm
content: Ok, that is some serious BU power - planning on jump starting the local nuke plant?An old pic of the time nuttery section of the garage. It's worse now `Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 11, 2020, 08:43:36 pm
content: Hehe.... Not nukes but I plan to start a WWVB2 in FloridaAs far as garage goes, that's not too much. I have 4 similar size racks in half of my garage and it's almost full. I ended up with many of the same like you did. I have quite a few HP8568B RF sections. Also VNA, lots of scopes, power supplies, etc, etc, etc. It's kind of sad that some of these things aren't worth the shipping that they'll require. Otherwise, we can do some serious swapping... HP8568B are serious RF parts machine. All work so I know parts are good. I've given parts away from junked ones.Initially, I wanted to have ONE BIG UPS and avoid all these. But soon, it became apparent that wiring alone will be quite a job to put one 10KVA UPS but it will also create a single point of failure. So after getting the first 3KVA, 2KVA joined. Rest is divided by functions. They multiplied.I'm sure there are some funny business going on in my lab at night. Mysterious increase in number of equipment is known to happen there.

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 11, 2020, 09:49:36 pm
content: Uhhh... That's just the corner of the garage. Why do i have a feeling we've just been running up the bids against each otherBut, I agree - I have way too much as it is and am planning to get rid of as much as I can. I have pieces that I want for the collection, but it's the repairing and refurbishing that I truly enjoy. Probably why so much of what I have is early 80s and prior HP - all it usually needs is a good cleaning, a little tweaking and a good 'ol Rifa purge. Although, there are quite a few Power Designs as well - and I'm really tempted to stipulate in my will that I'm to be buried with a pair of C500's.In seriousness, though, if you are in FL that would not be that bad shipping wise since I'm in north Alabama - the Decatur/Huntsville area. And, stepping back and looking at the capacities and numbers you seem to be dealing with - would not a standby generator make sense? Not just the equipment, but the house(?) as well? I'm in the process of designing (well, OK, talking a lot and letting someone else design) a new house and a good standby generator was a must; not all that expensive all in all and the power won't even blink. Maybe a small constant conversion UPS for anything truly critical?Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 11, 2020, 10:31:28 pm
content: I've actually thought of a whole-house generator, because when we get hit hurricanes a lot. Probably like a decade ago now, we got hit by THREE. Actually, one hit us on the way east, increased size in gulf, and came back and hit us again. So it was FOUR. We kept our plywood covering up.One issue though is FUEL. We have no city gas line here in my area. Gasoline has a shelf life. So how do I feed it? I have a small stand-by generator so I can keep a mini-fridge up for medication, and few lights. That's the extent that's feasible under the circumstances.I do enjoy repair and rebuild as well. That's pretty much 60% of my hobby. I have a local business I can drive up and get a truck full (if I had a truck) That's how ended up 12 spectrum analyzers. By the way.... I like dealing with junk stuff CHEAP. One to rebuild, two for parts, kind of things. I'm not organized enough to send you a spreadsheet, so we are not bidding on each other's stuff YET.

author: tkamiya
author_rank: Super Contributor
timestamp: February 12, 2020, 12:21:29 am
content: An idea I've been toying with.... not a backup power source but similar in concept:Solar power industry is full of cheap/inexpensive/probably_re_purpose-able charge controllers I have been thinking of using solar as MAIN power source for my always-on equipment, like time standard, and fail-over to mains when battery is down or at night. If I'm reading notes correctly, some controllers and inverters works without batteries by hooking up directly to solar cells.It will probably not pay for itself kind of proposition, but I think it's full of possibilities.Oh, why do I complicate my own life on purpose?

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 12, 2020, 04:00:37 pm
content: Re generator fuel - diesel. With proper care and treatment has quite a long life. I personally would rethink the whole solar thing, at least as a backup power source; seems to me that solar panels would be the first thing to go in a hurricane. Out of curiosity, what part of FL? I've spent a *lot* of work related time there. As to the equipment, I would be interested in trading some info if nothing else if you are interested. I have a *ton* of parts both HP and general, and I would be very interested in your SpecAns. My daily driver is a IFR 2399B, but I have been looking for an older HP. If you want to talk along those lines further, please PM me so we can get it off the thread.Thanks,Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 12, 2020, 05:12:28 pm
content: Right! I'm not thinking of solar as a backup. I'm thinking of it as main power with quick switch over to mainS. What I make has to be movable so I can shelter them during hurricane.I am in a city called Apopka. About 10 to 20 miles from Orlando.About shipping stuff.... My problem with shipping large and heavy stuff is multi-fold. Cost is #1. Equally important is lack of my ability to move, box, lug around heavy objects. Say SpecAn.... if you can somehow come here and pick your own, it's not a problem. But I'll have to pull a few out, test them out, box, and lug it to the UPS store. Due to my physical limitation, I am not able to do that. If you want parts from it, that's different. I'd be glad to help you out. I had to get some help to get all 12 of them into my garage.

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 12, 2020, 08:57:00 pm
content: I know exactly where it is - stayed there several times when working in Orlando although usually wound up in the Holiday Inn on International (good food and the slingshot ride)Sorry about the issues shipping - maybe a road trip for me and the way better half.Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 12, 2020, 10:12:58 pm
content: The HP105B arrived. Unfortunately, there are issues. When powered on, relay inside buzzes. Output are all over the place. Meter reading isn't right. Fortunately, the seller gave me a major discount, so I agreed to keep it as "parts or repair" unit. For that, I'm glad. Physically, it's in a beautiful shape.It has an HP10811 type OCXO, so it has to be a newer design. I don't know exactly which kind, yet. (or if it works even...)I'll be going through it hopefully soon. Design itself is pretty straight forward, so it shouldn't be much of problem repairing.

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 13, 2020, 03:00:25 pm
content: Wish you the best of luck with it! I got a second one a while back and haven't yet had a chance to go over it... The one that I've had for a while worked as received with only minor adjusting to the freq. Of course, every piece of equipment like this we get is really a roll of the dice - even if it works perfectly at the seller's there is nothing short of a anvil that FedEx can't break during shipping (and even that if it is handled by the USPS at some point.) I need to go over it soon and pick one to sell and one to keep; just hope it is in good a shape as the first. Let me know if I can be of any assistance when you start working on yours.Hal

author: HalFoster
author_rank: Frequent Contributor
timestamp: February 13, 2020, 03:08:54 pm
content: Do you already have the manual for it? If not, ArtekManuals (http://artekmanuals.com/) has excellent copies at very reasonable rates. For free manuals, check out Simon Schroedle's (of Simon's Dialogs) site (http://www.schroedle.de/m_list_wp.html) - it requires a password, but just follow the directions to request it.Hal

author: tkamiya
author_rank: Super Contributor
timestamp: February 13, 2020, 03:20:10 pm
content: When I was buying LOTS of FRK and PRS10, I made a tester. While there was none that was DOA, I found a few output just disappears after a while. Fortunately, the seller exchanged it for me. (then he black listed me!)I'm looking forward to work on HP105B. It's such a nicely build unit, it is almost an work of art. I really wish I can bring it back to life.By the way, I like keeping two of everything. Two makes it obvious when one goes off alignment or develop issues. Also, one can act as a trouble shooting aid. Why are HP105B so expensive on eBay? They are always >$500 and some twice that. They are 40 year old equipment!YES on manual.

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: February 14, 2020, 04:11:36 am
content: tkamiya,Your 105B should have the 10811-60109 version installed. Most of them will provide Allan Deviation of around 5 or 6 X 10-13th from 1 to almost 100Sec once allowed to warm up for a few weeks.Cheers,Corby