Another epicboring photo story from Ero-Shan.
After a period of dearth on evilbay, I finally found something that piqued my interest. Amazingly, there was a Nixie counter for a moderate initial price, and not a single bidder.
Did I not see anything that all others saw clearly? Something that escaped my eyes? Did everyone know just know how bad this counter was but me? The manuals are there prominently at the usual places, so there was no holding back.
I actually stayed the only one interested, and so acquired my first hp 5254L (with 5253B converter) for 50 bucks + 10 shipping.
To quote the manual:
The model 5245L features solid state design, low power consumption, small size (5-1/4 inch panel height), light weight (32 lb), ...
(emphasis by me)
The low power consumption is around 90 watts, a little more than 100 watts with the 5253B.
But one thing's for sure: This instrument was an engineering marvel in its days. Built without a single IC, and not just 6 digits up to 10 MHz. An oven for the crystal, remote control, output for recorder, 9 decade divider, plug-ins.
I was bewildered to see that the BCD-to-decimal decoder using neon lamps and LDRs, a setup that certainly wouldn't have occurred to me. And then I learned that the lamp are also used to store the count!
What an amazing piece of technology this is!
The seller promptly shipped the instrument, and when I got home this Wednesday, I spotted a big box under the stairs leading to my front door.
I eagerly grabbed it, but something wasn't right. The whole thing just wasn't rigid enough. I didn't like the foreboding it instilled in me.
When I finally opened the carton (after taking pictures), this is what I found:
Lots of unconstrained air and 3 lousy shoe boxes. The counter was free to move wherever it wanted. In contrast to some of you, the highest priority on my packaging list is: Ensure that the goods are secured so they can't move within the box. Then only a small layer of damping material is needed.
Amazingly however, the machine looked like it survived the trip in rather good condition:
The knackered time base knob was like this on the auction picture. Almost devoid of stickers!
And, as a surprise, the box contained both manuals, too:
I guess some sellers would expect the amount I paid just for those ...
Encouraged by the orderly outside appearance, I connected it to my variac and gave it a try. A thunderous, heart stopping rattle ensued when I switched it on, but the Nixies where lighting up ... not completely. The rattling clearly must be the fan, so I let it run. The leftmost digit was only half lit (yes, really, just the right half!), and the 4th was dark. It also would not do anything during the self CHECK. However, the fan got quieter after a while.
I knew I should have opened it before plugging it in, but, well, I just like to see how they behave before I intrude. Now is the time for opening the beast. Yep, several cards don't sit straight in their notches, and the edge connector only barely sits on the oscillator assembly. Manually turning the fan I find nothing wrong.
After making sure all cards sit firmly and the oscillator is also connected, I give it another try. The same helluva noise, but the display is now complete, and the CHECK function shows the expected value! When the fan noise had died down to a bearable level, I connected the input to my GPSDO:
Not too bad.
After an hour the figure went up to about 10000.050 kHz. There are no less than three trimmers for the oscillator: course, (unnamed) and fine. After some fiddling, and with 10 seconds gate time, I arrived at this:
I like it. (Of course this is just a stunt, but I still like it.)
First I take care of the fan.
A careful inspection shows that some blades touch the bobbin of the motor winding when the axle is closest to the motor. It also needs some cleaning:
The blades can easily be bent individually, so the noise can be taken care of.
And then I made that fateful decision.
You all saw the mains connector. Using my special cable is OK for a bit of playing around, but forbids itself for real usage. The connector needs to be changed to a modern IEC one. (Does anyone know a good name for that shape? I'm not aware of any. It certainly is neither an ellipse nor an oval. Long circle?)
My attempts at getting the rear plate out where of no avail. It seems you have to disassemble the whole instrument completely, which I'm not willing to do without a better reason.
So it has to be done right there. Now way to unsolder the socket. The compartment is cramped (even the Schaffner is discrete):
Let's first loosen the voltage selector and the socket to get better access. Why do they have to use rivets? I hate those damn things! And sure enough, I cock up drilling the rivets. I get 3 of them off center. This not only makes a mess, but it also keeps the rivets in place. I use my Dremel (which is not a Dremel) to get them out somehow. Looking at what I've done, I'm so devastated that I give up for the day.
Next day I realize that the IEC socket will not even fit in the available space. The voltage selector needs to move a millimeter down. And the holes from the old socket will not be hidden under the flange of the new. Don't ask how I made the opening ...
After around 4 hours it was finally done. I thought I'd better not show you the horrible outcome, but remembering med's fan botch, I gave in. I'm fully aware that I might get tried for crimes against a HO instrument, likely with nixiefreqq as prosecutor.:
I cleaned up the counter the best I could, swapped the knackered knob with one from behind and also tried the frequency converter. This is 500 MHz (490 + 10):
I must say that I'm more than pleased with this counter. 60 € was a real steal, IMO.
Now I've wasted 2 hours writing this story. It'l take at least as long to catch up.
TWO retaining latch knobs for the plug in? WHAT SORCERY IS THIS?
have seen lots of 5245's but none with twin latches.
won't even comment on what kind of pin headed bubble wrappin' shoebox stuffin' son of a bitch would just drop a 5245 into a box that way.
you are forgiven for your power connector bodge. ruined a pristine 5325b that way myself 30 years ago. was remorseful afterward and have never committed this immoral act again. (you only get forgiveness once. go forth and find some ph-163 cords and sin no more)
nice catch. be good to her.
ps one possible source of those cords are telescope shops. have an 8 inch celestron bought new in the late 70's that uses that connector/cord to power the clock drive)