Wanted: IBM 5153 Color Display (or a look-and-workalike - PGS HX-12?)

[VileR]

I'm looking for a CGA monitor for my 5160, in good/working condition. Trying here because I've about given up trying to source one from the usual channels.

Since the machine is IBM, I'd prefer the 5153, but I could also go for a CGA monitor with the same design, to preserve the look (Princeton's HX-12 is the only one I recall offhand).

Will pay a reasonable price, although I realize shipping won't be cheap. There was one on ebay recently that ended just south of €200, but the seller informed me that shipping would be €310... and that was from Italy, not exactly halfway across the planet. Wasn't expecting peanuts, but that's not my idea of reasonable.

That said: good protective packaging is vital with these fragile old things, so that part of it I will cover gladly. I'd rather pay a little extra than see another vintage monitor end up as a plastic jigsaw puzzle...

 

[Stone]

I'm looking for a CGA monitor for my 5160, in good/working condition. Trying here because I've about given up trying to source one from the usual channels.

Since the machine is IBM, I'd prefer the 5153, but I could also go for a CGA monitor with the same design, to preserve the look (Princeton's HX-12 is the only one I recall offhand).

I've got a Princeton HX-12 in great condition but just the shipping is gonna be ~ $175 - $200.

 

[VileR]

I've got a Princeton HX-12 in great condition but just the shipping is gonna be ~ $175 - $200.

That's still far more reasonable than the €310 quote from the eBay guy.

Do you happen to know if the HX-12 can be safely powered from the XT's auxiliary power output?

Reason I'm asking - the 5153 takes both 120V and 240V mains. The HX-12 (from photos, anyway) seems to be rated for 120V only.
We get 240V/50Hz here, but I have a step-down transformer that works fine with my (American) 5160, so if I could use the 5160's auxiliary output that might help.

(I don't know whether my transformer outputs 50 or 60Hz, but I'll have to find out anyway...)

 

[Stone]

It probably could but it's rated at 70 watts so if your 5160 has the 130W PSU it might not be able to keep up with demand.

Alternatively, you could run the 5160 directly from the 240V you have there and use the transformer for the monitor.

 

[modem7]

Do you happen to know if the HX-12 can be safely powered from the XT's auxiliary power output?
Reason I'm asking - the 5153 takes both 120V and 240V mains. The HX-12 (from photos, anyway) seems to be rated for 120V only.
We get 240V/50Hz here, but I have a step-down transformer that works fine with my (American) 5160, so if I could use the 5160's auxiliary output that might help.

It probably could but it's rated at 70 watts so if your 5160 has the 130W PSU it might not be able to keep up with demand.

For the 5160's PSU, the 130W rating is in regards to the DC output voltages (per [here]), i.e. excludes the auxiliary power output.

(I don't know whether my transformer outputs 50 or 60Hz, but I'll have to find out anyway...)

A step-down transformer modifies voltage only. The frequency out will be whatever is fed in,

 

[Stone]

For the 5160's PSU, the 130W rating is in regards to the DC output voltages (per [here]), i.e. excludes the auxiliary power output.

Right, it's just a passthrough.

 

[VileR]

Dang... looked at the schematic for the HX-12, and it uses a power transformer rather than a switching supply. So it looks like a bad idea to feed it a lower AC frequency than it was designed for.

 

[modem7]

Dang... looked at the schematic for the HX-12, and it uses a power transformer rather than a switching supply. So it looks like a bad idea to feed it a lower AC frequency than it was designed for.

According to [here], only a "very small percentage of equipment" is affected. Maybe a forum member who is an electrical engineer, might comment.

 

[VileR]

According to [here], only a "very small percentage of equipment" is affected. Maybe a forum member who is an electrical engineer, might comment.

Thanks. I understand that as referring to a small percentage of all electrical equipment; this one is more specific to devices with a power transformer in the AC input stage: https://www.edn.com/design/componen...sformer-at-a-frequency-it-wasn-t-designed-for

Interestingly the IBM 5153 does use a switch-mode power supply instead, which should be fine with a lower frequency than rated. But yeah, I'd be more confident if someone knowledgeable could comment.
The schematic for the HX-12 is here BTW, but these look like the relevant bits:

 

[modem7]

.
I see in the service manual for the HX-12, "Power Supply: 120V, 60Hz (220/240V, 50Hz available)".

.... this one is more specific to devices with a power transformer in the AC input stage: https://www.edn.com/design/componen...sformer-at-a-frequency-it-wasn-t-designed-for

Good information. Based on my understanding of the information there, which may agree with your understanding:

* If the 120 Vac 60 Hz version of the HX-12 has a 50/60 Hz rated power transformer (which is really a 50 Hz rated power transformer), there is no problem.

* If the 120 Vac 60 Hz version of the HX-12 has a 60 Hz rated power transformer, and the power transformer is used close to its maximum rated power, the information suggests that you would need to step your 240 Vac down to about 100 Vac (50/60 x 120V), else risk possible damage to the power transformer. Besides the issue of an appropriate step-down transformer to do that, there is also the issue as to whether or not 100 Vac is sufficient for the design of the 120 Vac version of the HX-12.


For the 120 Vac 60 Hz version of the HX-12, there is a possibility that the maker used 50/60 Hz rated power transformers in some units, and 60 Hz rated power transformers in others.

Maybe you get the present owner of a HX-12 (120 Vac 60 Hz) that you are thinking of acquiring, to open up their HX-12 to see if there is a part number (or other information) on the power transformer. Such a part number may reveal the frequency (and power) rating of the power transformer, which you would be hoping to be either 50 Hz or 50/60 Hz.

Of course, another possibility is to substitute the power transformer.

Maybe (since a particular decade?) it has been standard practice for engineers to incorporate in their designs, mains power transformers that are rated such that they will tolerate either 50 or 60 Hz nominal.

 

[VileR]

Those are all good points. But with the inevitable costs of packing/shipping such a thing, I should probably look for a unit with less question marks about it.

So, still looking for:
* an IBM 5153 Color Display (of any voltage/frequency rating)
* Or, a Princeton HX-12 CGA monitor rated for 50Hz (or 50/60 Hz) operation

 

[VileR]

I have a 5153 on the way, so for the time being I'm not looking any longer. But in the not-exceedingly-unlikely chance that it arrives in jigsaw-puzzle form, I will update.