Pyramid PS35G Schematic Needed

[W8GZW]

I am in need of a schematic for the Pyramid PS35G power supply and would be willing to pay for a copy. Thanks

Jeff

jpeel1@cinci.rr.com

[K1CJS]

I'm not saying you won't find one, but I've been looking for a Pyramid schematic too--and I can't find the one I'm looking for.  I've a feeling that info is not really available.  I was looking to find the voltage level feeding the fan which had gone bad.  I ended up cutting the original fan feed wires and connecting a 12 v computer case fan to the 12v output.  Ended up with better cooling and quieter operation that way.

[KE3WD]

Why didn't you just disconnect the bad fan's leads and use your meter to determine the type and amount of voltage? 

73

[AD4U]

From my experience Pyramid schematics do not exist.

If it is a typical linear supply, it can't be too complicated.

Dick  AD4U

[K1CJS]

Why didn't you just disconnect the bad fan's leads and use your meter to determine the type and amount of voltage? 

73

I tried it.  Seems like the circuit went bad and caused the problem--voltage reading was zero.  The fan might have been good, but it didn't work on 12 volts either.  I just sh*t canned the whole thing--circuit and fan.

[AH6RR]

Jeff I sent a PDF scan to you of the Schematic. If anyone else needs this also let me know.

Roland AH6RR

[W8GZW]

Thanks Roland, I very much appreciate the gesture !!

Jeff

[K1CJS]

Jeff I sent a PDF scan to you of the Schematic. If anyone else needs this also let me know.

Roland AH6RR

I would much appreciate getting a copy if you would e-mail it to me. 

Address is K1CJS@live.com  Thanks!

[W9GB]

Send the Pyramid power supply schematics to Repeater Builders TIP (RBTIP) ... and it can be available to EVERYONE.
http://www.repeater-builder.com/rbtip/
Repeater Builders has over 28 thousand files occupying eleven gigabytes (11 GB) of server space.
All of it is FREELY downloadable information, and their servers transfer (i.e. downloads) over 80 Gb per month!
===
The current production power supplies by Pyramid Car Audio (NY) are available on their web site.
Power Supplies - Page 1
http://www.pyramidcaraudio.com/items.asp?category=Power+Supplies+/+Inverters
Power Supplies - Page 2
http://www.pyramidcaraudio.com/items.asp?category=Power+Supplies+%2F+Inverters&varpagenum=2

1. SELECT the MODEL you have (hyperlink on web pages above)
2. Manual for that Model will be highlighted on left side of product web page.
3. Click on link to Download the Manual.
4. Schematic is found on last page.

Pyramid Car Audio does not have schematics OR provide support/repairs for the earlier (legacy) DC power supplies
imported from Eastern Asia, when Pyramid was known by a different name corporate name (1970s/1980s).
HOWEVER, they use the SAME basic LM723 regulator and NPN pass transistor (2N3055, 2N3771) design that
Astron used for years -- SO repairs for the DIY radio amateur are to follow Astron tips at RBTIP.

Pyramid's shortcomings with these legacy units are:
Using undersized heat sinks [they added fans to current design to address thermal issues];
lighter gauge steel for chassis; minimal uFd and VDC ratings for electrolytic capacitors; low cost unskilled labor --
which is apparent in their 1970s/1980s production units that I have repaired/rebuilt on the bench.
Some units do not have a crow-bar or over voltage protection circuit.

--- IF you have a broken unit, my suggestion is the same as Mike Holmes (HGTV) - REBUILD IT RIGHT ! ---

Repeater Builders - Linear Power Supplies 101 (educational)
Astron is the example. Pyramid traditionally has been the low price / cut-corners offering.
http://www.repeater-builder.com/astron/astron-intro-stuff.html

w9gb

[K8AXW]

The Pyramid power supply that I worked on had the exact same PCB as those used in the Astron power supplies.  The Pyramid is pretty much the same all the way through.  If push comes to shove, try using the Astron schematic to help you get through troubleshooting.

[AH6RR]

I sent a copy to you Chris K1CJS and also to Repeater Builder and to BAMA so I hope everyone can get theirs fixed they are a good power supply.

73
Roland AH6RR

[K8AXW]

6RR: I'd like a copy of the Pyramid power supply too!  Never know when another one will show up on my doorstep.  You can send it (if you will, that is) to K8AXW@arrl.net or aibling328@yahoo.com.

'ppreciate it.

[K1CJS]

Received it OK.  Thanks, Roland!