My PS-23ish project

Discussion in 'Homebrew and Kit Projects' started by AC9QC, May 19, 2017.

ad: L-HROutlet
ad: l-rl
ad: l-gcopper
ad: L-rfparts
ad: Subscribe
ad: l-assoc
  1. AC9QC

    AC9QC Ham Member QRZ Page

    Well, where to start; I'm pretty deep into building my own PS-23 substitute power supply. Yeah, I have more into this than one off Ebay would have cost before rebuild, but what's the fun in that? I'm using a combination of new buys, junk box parts, hamfest parts and recycled other stuff. I have a 3K 225W resistor I intend on load testing this with, and that will likely get hooked in series with one or two of my 250 ohm 50W resistors I have for my dummy load.

    [​IMG]

    This is the first section, it's for 300V. I dremeled the board up with an engraving bit. It's crude but it seems to work well and make nice, wide traces.

    [​IMG]

    A PC PSU makes a great source of snap-in capacitors and a hunk of the PCB can be used as a template for drilling their holes too.

    [​IMG]

    All snapped in. Never mind the holes in my log book made in haste!

    [​IMG]

    Rest of the holes for this side. I ended up putting the doubler circuit on the other side.

    [​IMG]
    The down side is that the solder seems to "flatten" considerably due to the surface area conducting heat the way it does.

    [​IMG]
    Some salvaged PC PSU parts; I had to supplement these with a Digikey order.

    [​IMG]

    300V and bias board ready to go.

    [​IMG]

    Here's the HV board. It's extremely simple, much like the original Heathkit was. The center rectangles are where the diodes will go ultimately, and the 2 holes in the middle are for the AC.

    [​IMG]

    The two nearly assembled boards ready to go.

    [​IMG]

    Inside of the chassis. Since I measured the main power transformer at 360-0-360 and I need 720ish volts and 300ish volts I'm going to be a bit over after capacitance is added. Yikes! I added a few resistors accordingly. Main B+ will likely still be higher than the original PS-23, but I've read of other OEM units running higher on a pair of 6146es and it's still within the range Heath gave for the HW-101.


    [​IMG]

    The boards are going to be mounted on top (protective plastic below to prevent shorting from the PSU I'm using as a chassis) and from left to right:

    7HY choke salvaged from a GE Mastr TX power supply
    5HY choke from Digikey, new Hammond
    50VCT transformer from something I took apart years ago and can't remember. Reel-to-reel maybe?
    Hamfest power transformer. 720VCT, 12V and unknown center tapped green winding.

    You can see the connector on the side of the chassis from this view, it's above the left PCB.
     
    AF6LJ and KE4OH like this.
  2. AC9QC

    AC9QC Ham Member QRZ Page

    Took my 225W 3K resistor and did a little load testing. I got 780V for my HV and 330V for my MV. I think that will drop down some more to about 290V when I have it at the full 150mA, and the plates will see about 800V when I have full B+ applied. I'm thinking it's time to start hooking stuff up to connectors, I have an HW-12 that will probably get hooked up first provided I don't have to do a ton of work to make the cables.
     
    AF6LJ likes this.
  3. K9STH

    K9STH Ham Member QRZ Page

    You need to drop the lower B+ at least 50-volts if you are going to use the power supply with an HW-12. Heath provided the 2-different lower B+ availability on the HP-23- seres (and the PS-23 which is the same as the HP-23C) so that the power supplies could be used with a much wider range of Heath equipment besides the HW-10X and SB-10X series. Even the SB-110 / SB-110A require the lower voltage not forgetting the mono-banders, the MT-1, MR-1, HX-20, and HR-20.

    Otherwise, if you use the power supply with the higher low B+, you are going to have problems and may even damage the HW-12.

    Glen, K9STH
     
    K3XR likes this.

Share This Page

ad: rfparts