The AM Forum

I have this Lambda MM-1 scope and it recently quit. I'm looking for a schematic and anything else to help me to repair this item. It is very small (1 1/2 Inch display)and sits on top of my 32V2.
I did look inside and found a split capacitor and low emission on the 6C4 which I believe is being used as the HV rectifier. After replacing both these items, I now have a very faint trace.
I see that this has been worked on before and don't know what others have done in the past..
Any help or information is appreciated...
Thanks,
Chuck   WB3LGG

I have a Lambda MM-2 and the documentation for it, would that be of any help?  The MM-2 was a kit consisting of a small 902 CRT with a 6C4 as the rectifier/sweep section, the grid of the 6C4 being used to produce a "sort-of" 60 Hz sawtooth wave as well as a retrace blanking function.

In mine, I found that all of the capacitors were bad, and wasn't surprised when I found they were branded "Micamold."  I suspect you will need to replace all the capacitors in this unit and also check the resistors for accuracy. The highest voltage is approx. 650 Volts.

Thanks for your reply, Sadly I'm just catching up with it..  Someone had told me about the MM-2 and I went on a search.  I talked to Pete (Manualman) and he looked into the MM-2 which he does have on hand and it uses the same CRT and 6C4. He told me that it was a kit which explains the poor workmanship! I did order a manual from him and also picked up a spare CRT on ebay which I'm waiting to arrive.  Thank you for your offer,  73,  Chuck

wow. There's a NOS 902 for $9.99 on the bay. I figured they'd cost more. There is also a $40 one.

Well please post pics of the scope, maybe before and after!! - and if permitted the schematic would be interesting.