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MT-615 Anal-O-Scope - Transformer Needed
Posted: Tue Nov 05, 2013 10:40 am
by serf2k
Hi All,
My first post here. I recently picked up a MT-615 from Kijiji (for $50) and it came with the manuals, some fuses and a bonus rat's nest in the front part of the unit. After cleaning out the nest, the internals didn't look too bad, but it was missing the 120v power cord (which had been carefully cut from the circuit junction points). A friend of mine and I have been diagnosing the internals, and it appears that the transformer (Primary voltages of 6/12/24 and 120v, Secondary voltages of 6.3/6.3/100/1000) may be toasted on the secondary coils. The manual shows that the power transformer is part number 7-2301, but they don't have it at Snap-On (not surprising, really). Would anybody know where I could find a replacement transformer?
Thanks,
Steve
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Tue Nov 05, 2013 2:05 pm
by macother
Steve,
I use that same scope, and have had issues, mostly related to leaky capacitors. I infrequently repair/restore/calibrate a variety of test equipment, and it's been my experience that component level parts are seldom sourced from the seller (snap on) but rather, are sometimes available from the manufacturer. I'm traveling now and won't be able to look at my scope, but I believe textronix was the manufacturer. Look at UL plate, it should have that information.
I further suspect that the power supply rectifier assemblage is a common type (no reason not to be), and there are several sources for replacement parts, including the transformer.
Good fortune,
Eric
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Thu Nov 07, 2013 3:32 pm
by serf2k
Eric,
Many thanks for responding! I will check the UL plate to see what it says. I expect that there has been some capacitor issues - as is often the case with most old electronics (I have a few old radios, an EM pinball and a jukebox so the transformer hum and warm glow of tubes is common around our place). I have been using a dim bulb tester and a variac to restrict the current and prevent "letting out the smoke". Thus far, I have determined that three of the four diodes (all made by National Rectifier) were toast, and I have assembled a full set of capacitors (thanks to Digikey, eBay and the Tube Store next door to my office) and will be recapping the entire set, including the cans. As far as the transformer goes, I have disconnected almost all the leads from their respective connections.....and I'm still getting a massive short according to the dim bulb tester. I will be disconnecting the secondary centre tap at the choke next to see if that helps....but if the short remains after all the wires are disconnected I'll be pulling the transformer. I'll post a reply here once I have done some more testing....unless I zap myself with the 1000 volt coil....that is
Cheers!
Steve
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Fri Nov 08, 2013 7:14 am
by serf2k
Well, I pulled the centre tap and remaining connections to the circuit from the machine. With the power off, I'm reading continuity (75k ohms) between all the secondary taps (6.3v, 100v and 1000v)....so the load side of the coil must be shorted.
There's no UL plate on the machine - it was one of the mobile scopes from 1958 that could be run off of the car's electrics so you could troubleshoot while driving (the line side of the transformer has coils for 110v, as well as 6/12/24v). If anybody comes across a NOS transformer for the MT-615 (or finds one for a Textronics that would run off of both 120vac and 6/12/24vac), please let me know.
Thanks!
Steve
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Fri Nov 15, 2013 8:31 am
by serf2k
Well.....got a similar scope off eBay today. I'll keep everybody posted on my progress.
Cheers!
Steve
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Sat Nov 18, 2017 6:42 am
by hurler99
Reviving old post, how do you tell if the Anal-o-meter works with no distributor/point car to hook it up to?
I turn mine on, light turned green and small traveling blip appears.
It is a silver circa 1958.
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Thu Nov 23, 2017 9:16 am
by serf2k
Hi Hurler,
The scope should have a harness at the back with connections to the coil and plug. I have a copy of the owner's manual, so I'll take a picture of the diagram that shows the leads. It should be fairly easy to do if you have an old car, but fairly difficult if you have something modern with coil-on-plug, etc.
Regards,
Steve
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Mon Nov 27, 2017 3:02 pm
by Bill_Houghton
I have to say, that sounds like something a proctologist would need.
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Fri May 31, 2024 3:58 am
by Gregorygoard
Re: MT-615 Anal-O-Scope - Transformer Needed
Posted: Mon Jul 01, 2024 4:10 am
by Gregorygoard