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Can anyone measure their PT's DC resistance?


 
3/19/2004 11:42 PM
Bradster Can anyone measure their PT's DC resistance?
In trying to use Duncan Munro's PSUD program to model power supplies (Marshall/Fender type) using Hammond transformers instead of OEM, alas, one needs at least the DC resistance of the Pri & Sec of a given transformer to use the program.  
(kind'a puts a crimp on using the software to help select a PT 'eh?)  
 
...so...  
 
Would anybody with any of the Hammond PT's listed below care to toss a DMM on them and post the DC Pri & Sec resistance? (or on any of the Hammond PT's for that matter) it would be very much appreciated for the list I'm trying to compile.  
 
270FX  
270HX  
272JX  
278X  
278CX  
(or any of the 3xx series)  
 
(I have emailed Hammond but they have not replied)  
 
And of course if you have any of the following Marshall or Fender PT's within reach I could sure use the DC Pri & Sec resistance on them to include in this:  
 
Marshall:  
T4145 DE (2203, 1959SLP)  
1202-164 (old 2204)  
1202-324 (new 2204 and 1987)  
0789-84 (JTM45)  
 
Fender:  
125P34A (100w Twin, Showman, etc w/4x6L6)  
125P5D (SR w/2x6L6)  
125P7D (BM w/2x6L6)  
125P23B (Deluxe w/2x6V6)  
125P1B (Princeton w/2x6V6)  
 
Along with a list, I will create some matching *.psu files to use with the PSUD program, to post for anyone who is using Duncan's freeware Power Supply design program, and yes before you ask, people have asked this same question over on Duncan's forum, nobody's got the info over there.  
 
All we need are a few kind soul's willing to take a couple minutes to measure these transformers and we can get a definative list useable with the PSUD software. Post it here or email me if you like.
 
3/22/2004 3:31 AM
Bradster2k Geez this cracks me up
Geez this cracks me up, I posted this question here and over on AX84, and like 1 person responded.  
(BTW thanks Dan).  
 
Now the reason this cracks me up is because nearly EVERYBODY who posts here has iron, and many have exactly the iron we need to get measured.  
 
C'mon fellow ampagers, it only takes like 35 seconds to measure your Pri and Sec DC resistance, please help us out compiling this list.  
 
 
(did I mention only 1 guy?)
 
 
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3/22/2004 3:39 AM
Mark Lavelle
I've got a few hammond PTs here, but none of 'em is on your list. Is there some reason you think everybody here should be using the models you mentioned? ;)
 
3/22/2004 4:07 AM
Bradster2k
No, sorry Mark, (and everyone else) I certainly didn't mean to sound as though I think everybody here should be using these models, good point, and thanks for bringing it to my attention.  
 
Those were just some Hammond numbers I was trying to model with Duncan's PSUD program and I though it might be better asking for some specific models might get better response than an open-ended query.  
 
Certainly any contributions would be welcome, specially any Hammond, and go far in helping to compile the list and make some *.psu files.
 
3/23/2004 6:46 AM
Mark Lavelle
Somehow I didn't catch that you were basically just looking to build a library of .psu files. I'd be happy to post whatever you get together on my site if you need somewhere to host it...  
 
Here are three I have on hand (that aren't in amps):  
 
Heyboer PT-250 (HTS-7110)  
   250-0-250/150mA; 6.3/4A; 5/3A  
   3.2 ohms primary  
   88.5 ohms secondary  
 
Hammond 270DAX  
   260-0-260/90mA; 6.3/3.5A  
   5 ohms primary  
   178 ohms secondary  
 
Hammond 269EX  
   190-0-190/65mA; 6.3/2.5A  
   11.8 ohms primary  
   275 ohms secondary  
 
...measured with a nearly new Fluke 175, and subtracting the 0.2 ohms the meter reads when you clip the two leads together.
 
3/22/2004 10:34 PM
bob p Re: Can anyone measure their PT's DC resistance?
270FX out of chassis:  
primary resistance: 9.1 ohms  
secondary resistance: 94.5 ohms  
(secondary measurement taken across hi-voltage leads.)  
 
secondary measurement from one hi-V lead to CT: 52 ohms  
 
hth
 
3/24/2004 6:09 PM
Bradster2k
Thanks Mark and Bob, I'll gladly add these to the list.  
 
Mark, yes, I would like to take you up on that offer to post *.psu files and perhaps you can even help with reviewing/editing them too if you feel so inclined? (I'll need an email address)  
 
Anybody else got any Hammond's, or how about Marshall, Fender, Heybower, OEI, Sovtek PT's?  
 
Here's what I've got so far:
 
Make/Model DC-Pri DC-Sec Advertised spec contributed by:  
___________________OHMS_____OHMS_______________________________________  
 
Hammond/269EX 11.8 275.0 260-0-260 90mA (Mark Lavelle, ampage)  
Hammond/270DAX 5.0 178.0 260-0-260 90mA (Mark Lavelle, ampage)  
Hammond/270EX 2.8 63.5 275-0-275 125mA (Budso, AX84)  
Hammond/270FX 9.1 94.5 275-0-275 125mA (Bob P, ampage)  
Hammond/271X 7.0 170.0 280-0-280 60mA (Budso, AX84)  
Hammond/272DX 3.0 61.0 300-0-300 125mA (Budso, AX84)  
Hammond/272FX 2.3 101.0 300-0-300 150mA (Dan Souder, AX84)  
Hammond/272JX 1.4 45.0 300-0-300 250mA (Philip Ruetz, AX84)  
Hammond/273BX 1.6 72.3 350-0-350 175mA (KM, ampage)  
Hammond/278CX 1.0 21.9 400-0-400 465mA (Jason D, AX84)  
 
Heyboer/PT-250  
(HTS-7110) 3.22 88.5 250-0-250 150mA (Mark Lavelle, ampage)  
 
 
Anybody else feel like jumping-in please do, the list can only get better. Looking for more Hammond's, Marshall, Fender, Heybower, OEI, Sovtek etc.  
 
Thanks to all who have contributed so far.  
 
-Brad
 
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