Tenna Pyramid Phase III Model PS-12

BobEmerson

unread,

Sep 3, 2006, 7:02:53 PM9/3/06

to

Good Day All,

I have recently come into possession of a Tenna Pyramid Phase III Model
PS-12 and guess what? It does not work. I am inquiring as to the
availability of a copy of a schematic for this device. If someone could
email me a copy of it, I would be grateful.

Thanks
Bob Emerson
bob.re...@gmail.com

Unknown

unread,

Sep 3, 2006, 9:33:53 PM9/3/06

to

"BobEmerson" <bob.re...@gmail.com> wrote in message
news:1157324573.0...@74g2000cwt.googlegroups.com...

Bob,

IF you are lucky - you may find someone that has a schematics for this
model.
http://www.repeater-builder.com/astron/astron-index.html

I would suggest that you get a copy of the Astron RS-12 power supply -- it
will be CLOSE.
http://www.repeater-builder.com/astron/astron-rs12a.html

Power supply uses the LM723 regulator IC (the most common for linear power
supplies of this type) AND pass transistors for the current handling --
usually 2N3055 or 2N3771.

Here is the 1996 DIY web article that spells out "how they work"
http://www.seits.org/features/pwrsup.htm

Repairing a linear power supply (education, tech sheets, troubleshooting) --
there are over 25 web pages here for any DIY of Astron, Pyramid, TrippLite,
etc.
http://www.kbt-dc-supplies.com/index.php

w9gb

Unknown

unread,

Sep 4, 2006, 11:58:43 AM9/4/06

to

"g. beat >" <@<spam protected> wrote in message
news:Ga-dnR2CZZQeH2bZ...@comcast.com...

> "BobEmerson" <bob.re...@gmail.com> wrote in message
> news:1157324573.0...@74g2000cwt.googlegroups.com...
>> Good Day All,
>>
>> I have recently come into possession of a Tenna Pyramid Phase III Model
>> PS-12 and guess what? It does not work. I am inquiring as to the
>> availability of a copy of a schematic for this device. If someone could
>> email me a copy of it, I would be grateful.
>>
>> Thanks
>> Bob Emerson
>> bob.re...@gmail.com
>>

Bob,

BTW, the LM723 will likely be soldered to the regulator PC board inside of
the Pyramid.

1. Carefully desolder the part (solder wick works best). NOTE, the
orientation of pin 1 on the PC board. The IC should have a notch for that
side OR a dot above pin 1 on the plastic top molding.
Dave Metz discusses this in the article -- I bookmarked in earlier message
for you (read this)

2. When you working with the LM723 regulator IC assure the large
electrolytic capacitors are DISCHARGED before removing OR inserting in the
socket (good way to destroy a perfectly good LM723).

Greg

BobEmerson

unread,

Sep 4, 2006, 2:42:59 PM9/4/06

to

Sir,

Thank you for the answers. I'm in the process of reading all the
material and trying to make sense of it all. Thanks again

Skipp says hello

unread,

Sep 11, 2006, 12:37:06 PM9/11/06

to

You are one lucky guy today Bob. I have a copy the Pyramid Power
Supply already scanned in. I've fixed one or two in my day. The diagram
might be of a slightly different model/size but you can easily use it
to fix your same type supply.

I'll email a copy of my pdf scan to your email address below. If you
don't receive it (about 1MB file size) drop me a note direct at the
email links found on the web page.
www.radiowrench.com/sonic

good luck with your repairs...

skipp
skipp025 at yahoo.com

: BobEmerson <bob.re...@gmail.com> wrote:
: Good Day All,

t.tucker...@gmail.com

unread,

Mar 26, 2016, 10:27:45 AM3/26/16

to

I could use a copy too ,mine does't work either. 313 715 3929, Bill Thanks

cene...@gmail.com

unread,

Nov 24, 2016, 11:58:37 AM11/24/16

to

On Sunday, September 3, 2006 at 7:02:53 PM UTC-4, BobEmerson wrote:

highlandham

unread,

Nov 25, 2016, 6:42:42 AM11/25/16

to

====================
Never heard of this device , what is it(an antenna matching unit?) and
what do you want to use it for .

Frank , GM0CSZ / KN6WH in IO87AT

Allodoxaphobia

unread,

Nov 25, 2016, 8:09:10 AM11/25/16

to

On Fri, 25 Nov 2016 11:42:40 +0000, highlandham wrote:
>> On Sunday, September 3, 2006 at 7:02:53 PM UTC-4, BobEmerson wrote:
>>> Good Day All,
>>>
>>> I have recently come into possession of a Tenna Pyramid Phase III Model
>>> PS-12 and guess what? It does not work. I am inquiring as to the
>>> availability of a copy of a schematic for this device. If someone could
>>> email me a copy of it, I would be grateful.
>>>
>>> Thanks
>>> Bob Emerson
>>> bob.re...@gmail.com
>

> Never heard of this device , what is it(an antenna matching unit?) and
> what do you want to use it for .

Why are you trying to talk to someone who *last spoke 10 years ago?*

Ralph Mowery

unread,

Nov 25, 2016, 10:50:38 AM11/25/16

to

In article <o19815$fcr$1...@dont-email.me>, highlandh...@rfburns.eu
says...

The message is about 10 years old.

However this is a power supply that supplies the nominal 13.8 volts (12
volts) DC from the 120 volt AC line. My guess that the PS-12 was good
for 12 amps maximum. Most of the time they are referred to as just the
Pyramid supply.
I had a 50 amp supply at one time, but it is not near as well made as
the Astron. They all seem to use the same basic circuit of the 723 IC
regulator IC and pass transistors.

Michael Black

unread,

Nov 25, 2016, 3:51:16 PM11/25/16

to

Someone I knew had an IBM 12V power supply forty years ago, I always
assumed it had been from a computer. I'm not sure how much current it
putout, something like 25amps or maybe more.

It was about half the size of the average computer case.

ANd it was linear.

Michael