Leader LBO-513A 15Mhz oscilloscope I got dirt cheap! - Page 1
Forum section: electronics / testgear

author: FoZzIzOz
author_rank: Newbie
timestamp: May 09, 2015, 12:31:49 pm
content: Hello all!I've decided to crawl out of my cave and finally register here on the forum!It only seems right for my first post to be about my second oscilloscope purchase, which I found on craigslist some months ago for only $10!!!This Leader LBO-513A had been sitting in a gentleman's basement for some years. He said he powered it up and was unable to get a trace to show up so I figured it'd be worth a shot at trying to repair, or would make a pretty night stand.He had bought it from a neighbor's yard sale many years ago and it came as is, with no probes. I cringed when he told me he used to shove wires into the BNC when using itI found a zip file with about 30 bitmap images of scans of the original manual, which I cleaned up and made a pdf with:http://frankfort-electronics.com/soapland/manuals/Leader_LBO-513/Leader%20LBO-513.pdfImagine my surprise when I got it home, hooked a probe up from my HP 54502a, and with a bit of knob/button play... the .5VP-P test signal appeared!!! A working 15mhz 'scope for only $10!!I later calibrated it (according to the manual) and it's worked rather well since.. I did notice a few of the pots on the boards are not mentioned in the manual. One curious tick is that at certain levels when triggering on a 1khz sine wave, an inverted waveform will appear along with the expected waveform, so that seems a bit dicky. Also the focus/intensity controls dont seem to clean up the trace as well when measuring <100mVP-P, but I realize this is from what I can tell a low end vintage 'scope.. so for $10 I can't complain too much. If anyone has any suggestions or ideas about tweaking the pots that aren't mentioned in the manual, please feel free to enlighten me as I am not a seasoned pro with EE or test equip.I found one IC in it (on the vertical board), a MPQ918 (Quad memory driver transistor) - date code 45th week of 1984All considered, it seems to work rather well and was a great deal.. perfect for a bit of portability as my HP 54502a, although much higher bandwidth, is much heaver, more fragile and more valuable.Hope ya'll enjoy the pictures, sorry they aren't breath taking. Let me know if anyone is interested in a video, or more pictures.Cheers!

author: Smith
author_rank: Frequent Contributor
timestamp: May 09, 2015, 02:26:46 pm
content: Nice addition to the collection! Looks like a descent unit. Although I like the HP more (yes, I got the same one).Its nice to get some cheap gear every once in a while from people who think its broken or unusable because they don't have a clue what they are doing.

author: Cliff Matthews
author_rank: Unknown
timestamp: May 09, 2015, 02:44:11 pm
content: That's the kind of scope everyone should cut their teeth on.. nice tactile controls and clear markings. Did you have to wash the panels to make it look this good? BTW your photos are good, thanks for sharingYou should see my Heathkit O-10 (maybe not, it makes my cry.. the vertical amp is kaput)

author: Johndi
author_rank: Contributor
timestamp: May 09, 2015, 02:50:14 pm
content: Nice score!

author: FoZzIzOz
author_rank: Newbie
timestamp: May 09, 2015, 03:09:59 pm
content: Thanks ya'll.Yeah I love my HP, had it for nearly two years and have gotten rather attached to Auto Scale and being able to key in values, also the measurement functions are golden.. which gave me a bit of a culture shock when I brought this one home!I agree Cliff, I am a bit backwards on which I got first! as for the inside, it was veryy dusty when I first opened it up. after I verified it to be working I tore it down completely and cleaned everything. Removed all knobs and soaked in rubbing alcohol, cleaned and lubed the pots with ratshack contact cleaner/lube, and scrubbed the crap out of the front panel. It was pretty dirty when I got it, the knobs were the worst.Oh noono need to cry! pop the panel off and get to it, my friend! haha.Thanks for the replies!

author: smjcuk
author_rank: Frequent Contributor
timestamp: May 09, 2015, 03:30:59 pm
content: Good win that. Well done.Got a Goldstar/LG 20MHz scope for £10 a few weeks back as well. Worked perfectly. Dont think the woman had any idea what it was or if it worked as it was her late husband's. Most of my gear appears to be from dead engineers.