HEATHKIT HP-23 -vs- HP23B Power Supply Filament voltage

[KC3GMQ]

Hi all,  I have a HP-23 Power supply.  I rebuilt it.  So my question is on the filament voltages. The HP-23 has 6 volt and 12 volt filament voltages.  If I short the HP-23 (per the book) to turn it on, and I check at those pins, I get 85 VAC on each the 12 and the 6 volt.  If you look at the drawing, and If I take a reading this way....there are 3 filaments coming from the transformer,  2 of them make 6 volts, the other two together make 12 volts.  Does this mean that my Heathkit SB-101 transceiver will make those connections to bring the voltage to what it requires.  Here is why I ask....I also have a HP-23B, it only has 12 volt filament,  but read at the pin it is 12 volts already.  Hope this made sense.  I think the HP-23 is the only one that can do 2 Filament voltages.

Thanks
KC3GMQ Dave

[N8ETQ]

Hey Dave,


    Pin 2 = Fil. Common

    Pin 6 = 12V Fil

    Pin 8 = 6V  Fil


/Dan

[KC3GMQ]

Dan I have that,  the questions is, when you read the 23B, you get 12 volt filament from the power supply.  When you read the 23 you get much higher.  The SB-101 and HW-101 can use any of the HP-23 series, 23, A, B and C, I am asking if the HW and SB series have the portion that connects the two and gets the correct AC voltage withing the transceiver.  It looks like it does.  I just tried it on a non working HW-101 and I got the correct reading at the tubes.  I didnt want to connect this HP-23 I questioned to a SB-101 I just finished.  I wasnt sure it didnt have an issue and I didnt want to fry anything.

Dave

[W1RKW]

load test the filaments windings on the 23 with resistors instead of attaching to the rig(s).

Also, check for leakage between windings. 

Be advised that the 23 and 23b maybe rig specific.  There are certainly some wiring/design differences in the filament circuit.

http://www.heathkit.nu/heathkit_nu_HP-23B.html

[KC3GMQ]

All,  I got this figured out.  The HP-23 23A, B and C are all a little different.  In the 23 (mine) It has both 6 vac and 12 vac filament voltages. the HP-23 had both so it could still be used with some older radios.  So Heathkit seems to have been a bit smart.  They made the power supplies output a specific way, and then depending on your rig, SB-XXX or HW-XXX depended how you wired the connector. You had to use the Rig manual to wire it correctly.  In my case...My SB-101 doesn't need the 6 vac from the power supply, It leaves this wire not connected. Also, In the SB-101, the switch when turned on will connect the 12 vac line and the center tap from that transformer making it 12 volt to the radio for filament.  I looked at other radios and each wired the plug, or had a position on their on off switch that made the connections needed to get what it wants from that power supply.  After the HP-23, 6 vac was no longer offered.  I hope I explained that ok,  I sm no wiz, but I am trying lol.  So this thread I consider dead now....Not sure if there is something I need to do to shut it down.  Back to my Apache issue lol  Thanks all.