Its nice to see theres still some people out there that know what they are talking about.
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Palomar Electronics Max-Mod. Spoiler alert!
- Thread starter nomadradio
- Start date
I recently purchased some Toshiba 2SA1301's from a US Source that carries NOS components. It does not look to be as large as the Palomar Max Mod voltage regulator. Shape is not the same either.To be honest I think I installed one of these in my first Gen RCI 2950 back in 1995 when the stock regulator went out. I ordered a sleeve of 15 Toshiba 2SA1302's also from the USA and NOS. I have not had time to order Mica or hardware. Both parts though are larger than the transistors used stock in most radio chassis's I have been in.
Since we do not care too much if the average heat sink temp increases a bit if the electronic parts run cooler maybe pop riveting a copper heat spreader onto the chassis internally to increase total heat sink area and heat conductivity might be an idea as well especially in base stations where space is plentiful. brass, copper, aluminum 1/4 to 1/2 inch thick running the length of one side if doable would work great. I know that is gross over kill since this part should never get that hot any ways unless you are doing something crazy like NPC or Super Swing etc...This sight though leans towards gross over kill though! LOL
I need to get a Palomar Max Mod now to compare. Does anyone have access to x-ray machine? It would cool to see what is inside the case of all 3!
Since we do not care too much if the average heat sink temp increases a bit if the electronic parts run cooler maybe pop riveting a copper heat spreader onto the chassis internally to increase total heat sink area and heat conductivity might be an idea as well especially in base stations where space is plentiful. brass, copper, aluminum 1/4 to 1/2 inch thick running the length of one side if doable would work great. I know that is gross over kill since this part should never get that hot any ways unless you are doing something crazy like NPC or Super Swing etc...This sight though leans towards gross over kill though! LOL
I need to get a Palomar Max Mod now to compare. Does anyone have access to x-ray machine? It would cool to see what is inside the case of all 3!
When I was in high school it was people arguing what was better made a Cobra 148 GTL or the Uniden Grant XL. That was back when Copper ran add's with the same radio photographed twice and said one was a Cobra 148 and the other was a Uniden Grant etc....Not that it mattered becasue the argument raged on! LOLIrrational, yes.
Found this pic I snapped of the inside of that mystical secret-sauce radio the "General Lee". Still brings a smile.
73
Another possibility is an MJW21193
If anyone believes that these are not rebadged parts... I have a bridge to sell you.
If anyone believes that these are not rebadged parts... I have a bridge to sell you.
TIP2955 In a modern, TO-247 package, looks like a winnner.
I use the NPN version (TIP3055) when space allows, haven't tried cramming a TIP2955 into an old Galaxy mobile yet, but I will get around to it one of these months, I don't see why it wouldn't work!
But, i'm no technician or anything so.. consult the datasheet, and form your own educated guess! (Because I didn't check if the "pin-out" matches,
)
I hope this is a good part to use.
I use the NPN version (TIP3055) when space allows, haven't tried cramming a TIP2955 into an old Galaxy mobile yet, but I will get around to it one of these months, I don't see why it wouldn't work!
But, i'm no technician or anything so.. consult the datasheet, and form your own educated guess! (Because I didn't check if the "pin-out" matches,
)I hope this is a good part to use.
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been using tip2955 for over 20 years with great results..only because the b754 is hard to find here till recent off the shelf and i use the tip series in alot of stuff besides transceivers
yes pin for pin the same
yes pin for pin the same
Thank you brother, I appreciate the pin-out confirmation!
Looks like that will be my go-to part for now.
Edit: Thanks to RabbiPorkChop, for sharing the Palomar "Max-Mod" data sheets.
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![[1]Palomar-Max-Mod-Datasheet.jpg](https://www.worldwidedx.com/data/attachments/18/18900-c0d6d9cedb0924596f6020f9164057f3.jpg "[1]Palomar-Max-Mod-Datasheet.jpg")
![[2]Palomar-Max-Mod-Datasheet.jpg](https://www.worldwidedx.com/data/attachments/18/18901-c68733af6f09267ae7be6101c946b555.jpg "[2]Palomar-Max-Mod-Datasheet.jpg")
Sixty Amps!?
Definitely not a 2SA1302. Same size package, though.
How do you get 60 Amps through a lead wire that small?
73
Definitely not a 2SA1302. Same size package, though.
How do you get 60 Amps through a lead wire that small?
73
-60 amps pulse...or surge
Its possible.
The die on the thing has to be huge and so do the bond wires. I still think its off the shelf.
I would like to see someone run that collector current all the way to 40 and hold it.
I bet it dies. I am not a believer.
That's a shitload of power.
Its possible.
The die on the thing has to be huge and so do the bond wires. I still think its off the shelf.
I would like to see someone run that collector current all the way to 40 and hold it.
I bet it dies. I am not a believer.
That's a shitload of power.
I wrote that a few times. As replacement I use BD250C. Fits perfect, no issues at all. 25A 125W is more that radios need.
Mike
Mike
Hmm. The Bourns' data sheet for the BD250 says 40 Amps peak collector current, but 25 Amps "continuous".
Makes me think Eric copied the "peak" rating for his part when editing his spec sheet.
Just doesn't say "peak".
73
Makes me think Eric copied the "peak" rating for his part when editing his spec sheet.
Just doesn't say "peak".
73
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