Old Hobart Suitcase welder diodes

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I have a old Hobart suitcase welder , the plastic suitcase one . tag says model Handler Spec 6969A . I'm getting ready to replace the diodes & was wondering if it was possible to double up on them ?& was reading some stuff on the web where guys have made their own diode banks with higher ratings . my welder takes 2 diodes . I replaced them @ 20 years ago  so I don't remember if I used stock ones or upgraded them . the replacement ones I have are marked 85HF60 . when I ordered them I bought 2 spares . is it worth it to double up on them & if so can someone tell me if it's just a matter of putting two right next to each other & hooking them up . also if anyone knows where I can get a schematic and or a manual for this welder that would be cool thanksanimal
Reply:You might get a response over in the Hobart Weld Talk forum if the Hobart "experts" are still on duty, or call Hobart customer service.  They have traditionally been very helpful.  Give them the exact model, spec number and any other identifying info.  Did your old diodes fry?  Paralleling semiconductors has its limits, but possible. Works best if they are all the same manufacturing lot & etc I believe.  A higher rated diode with proper heat sinking might be better if they fit.  You say 2 diodes?  Not a bridge rectifier arrangement?  Hmmm."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:yea , just 2 stud mount diodes mounted to a 5" x 6" 1/8" plate above the transformer.  the welder started actin kinda funky & same as it did last time @ 20 years back . I replaced the diodes & was back in business .thanksanimal
Reply:Must be a center-tapped rectifier arrangement.

"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Yes, go over to hobart's site and place a request in the contact us area. not on their forum.If no response call them after a few days. If they don't have the manual send me a PM I might but it is hard copy now.Then I have to find it again. The 85HF60 diode is still sold on newark electronics for less than 6 dollars each. Its an 85 amp diode rated at 600 volts.Has 1/4 inch stud . the NTE6076 is the same. the next step up is the NTE6156 150 amp diode. but it has a 3/8 inch stud.Hole would have to be drilled out. Just some ideas, If you have a local electronics store, go there and see what they can come up with.
Reply:

Originally Posted by ccawgc

Yes, go over to hobart's site and place a request in the contact us area. not on their forum.If no response call them after a few days. If they don't have the manual send me a PM I might but it is hard copy now.Then I have to find it again. The 85HF60 diode is still sold on newark electronics for less than 6 dollars each. Its an 85 amp diode rated at 600 volts.Has 1/4 inch stud . the NTE6076 is the same. the next step up is the NTE6156 150 amp diode. but it has a 3/8 inch stud.Hole would have to be drilled out. Just some ideas, If you have a local electronics store, go there and see what they can come up with.