#24696

This PS150 has been around for 20 years on my shelf and is now recapped.? Checking output voltages at 120VAC gives the following:

B+? 690v
LV 400v

These seem high though I know they will drop under load.? Does this seem reasonable for this PS?

#24699
Edited

Howdy,
You might consider putting a variac on it and loading both the high and low voltage B+ to see where they are.? I have found that modern line voltages do increase the output voltages a bit.

--
73/Rick
WA6III

__________________________________
No critters were injured transmitting with Hallicrafters transmitters except
the ones that wandered into the final amp cage Bug-Motel!!
Bugs check-in, but they don't check-out!

#24700

I should also add (after my HT45 Loudenboomer power supply experience) that if you do not have a load on a choke input power supply, the voltage can measure pretty high.
--
73/Rick
WA6III

__________________________________
No critters were injured transmitting with Hallicrafters transmitters except
the ones that wandered into the final amp cage Bug-Motel!!
Bugs check-in, but they don't check-out!

#24701

开云体育

Seems reasonable for no load condition.

?Walt Cates, WD0GOF

?

Your past has no control over your future. Only your NOW can impact your future.

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From: [email protected] <[email protected]> on behalf of Lionel B <N5LB@...>
Sent: Friday, October 28, 2022 11:07 AM
To: [email protected] <[email protected]>
Subject: [HallicraftersRadios] PS-150 PS voltages

?

This PS150 has been around for 20 years on my shelf and is now recapped.? Checking output voltages at 120VAC gives the following:

B+? 690v
LV 400v

These seem high though I know they will drop under load.? Does this seem reasonable for this PS?

#24702

开云体育

everything you ever wanted to know about 150/500 PS.

olympus digital camera hallicrafters power supplies ps-500 specification 500 series power supply user manuals 150 series power supply user manuals ps 150/500 rear panel build ps 150/500 test fixture ps test fixture setup hallicrafters transformer specs regulating vintage power supplies p-2000 restore modify drake ac4 to ps-150 modify galaxy 400 to ps-500 modify galaxy 400…

wd0gof.com

?Walt Cates, WD0GOF

?

Your past has no control over your future. Only your NOW can impact your future.

Show quoted text

From: [email protected] <[email protected]> on behalf of Lionel B <N5LB@...>
Sent: Friday, October 28, 2022 11:07 AM
To: [email protected] <[email protected]>
Subject: [HallicraftersRadios] PS-150 PS voltages

?

This PS150 has been around for 20 years on my shelf and is now recapped.? Checking output voltages at 120VAC gives the following:

B+? 690v
LV 400v

These seem high though I know they will drop under load.? Does this seem reasonable for this PS?

#24716

All great information and thank you.?

I have found that R201 one of two wirewound 15k 2W bleeder resistors is open. R202 is good at 14.7k.? I wouldn't have thought an open bleeder could result in high DC out.?

#24717

30K at 575v is a pretty decent pre-load!
About 20ma.?

That’s 6 watts for each resistor and a total load of 12 watts.?

#24718

开云体育

If it is a 2w resistor that is probably why it is open. The bleeder resistors are 15K 10-watt. I replace them with 20K 10-watt resistors, which reduces the heat dissipated in the chassis. It still bleads off the charge fast enough to be safe.

?Walt Cates, WD0GOF

?

Your past has no control over your future. Only your NOW can impact your future.

Show quoted text

From: [email protected] <[email protected]> on behalf of Lionel B <N5LB@...>
Sent: Saturday, October 29, 2022 11:38 AM
To: [email protected] <[email protected]>
Subject: Re: [HallicraftersRadios] PS-150 PS voltages

?

All great information and thank you.?

I have found that R201 one of two wirewound 15k 2W bleeder resistors is open. R202 is good at 14.7k.? I wouldn't have thought an open bleeder could result in high DC out.?

#24723

Right, 10 watt 15K.?

#24738

Greetings to the Group:

I have given up on the original Hallicrafters PS-500 design.?? If you look at the various documentation, the SR-400 Cyclone (the radio that it is supposed to power) specifies a low B+ of 270 volts.?? The power supply documentation specifies 280 volts at 100 mA.?? Yet, if you look at the SR-400 schematic carefully, you will find that the minimum possible current drain for the unit on receive is about 140 mA due to fixed loads such as the 0A2 regulator circuit and the PA screen bleeder resistors.?? The actual measured load on receive is 183 mA.??

I found no combination of chokes and filter capacitors that would prevent the receive voltage from exceeding 280 volts and still allow the voltage to be reasonable in transmit; the voltage swing was well over 20 volts.?? In order to keep some of the voltage sensitive circuits like the heterodyne oscillator circuit working as well as possible in transmit, I found it necessary to more or less completely re-design the power supply.?? The low B+ in my PS-500 is now regulated.

Please find the as-built schematic attached.

--
Jim T.
KB6GM

Cyclone PS-500 As-Built reg.pdf