Radio shack Kit Question on transformer

Ken · Dec 30, 2005

Hello,

I have a kit that I bougfht from RAdio Shack , Here is a link of what I am
talking about. (
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=6019532542&indexURL=
)

I would just like to know what are on the transformers in this kit , There
are no part numbers and I need to replace that part.. The only information I
have is what is written on the board:
Output Transformer
900 8
----- -------
-
-----
-
----- ---------
Three legs going in and two out with these numbers on top.
Thank you for your help

Ken O

Don Bowey · Dec 30, 2005

On 12/30/05 12:03 AM, in article
K5btf.6401$l87.729761@news20.bellglobal.com, "Ken" <lerameur@sdom.com>
wrote:

It is an audio output transformer, 900 Ohms to 8 Ohms, to connect to an 8
Ohm speaker. The 900 Ohm side may be center tapped.

Don

DaveM · Dec 30, 2005

"Ken" <lerameur@sdom.com> wrote in message
news:K5btf.6401$l87.729761@news20.bellglobal.com...

It's just a plain old audio output transformer. You already have the most
important specs: 900 ohms primary impedance with a center tap, 8 ohms
secondary impedance. Since this is a learning kit, I'm assuming that it is
low power, maybe a few hundred milliwatts.
I suggest one such as this from www.mouser.com as a close replacement:

Catalog # 42TU008
Primary 800 ohms CT
Secondary 8 CT
400 mw
$ 2.19 each

It's not an exact match, but, since it's an experimenter's kit, it's
insignificant. It will still work in the kit.
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!

Jasen Betts · Dec 30, 2005

On 2005-12-30, Ken <lerameur@sdom.com> wrote:

looks like a transformer giving 900 ohms centre tapped on one side and 8
ohms on the other. these were popular in early transistorised products
(especially those that used 9V batteries)

if that's one of those "30 in one" "learn electronics" type kits
any audio transformer that's a "ballpark" match should work.

For example Jaycar cat# MM-2532 "1000 ohms CT to 8 ohms" (www.jaycar.com.au)
I expect there's a supplier nearer you with a similar product.

Bye.
Jasen

ian.field1 · Dec 30, 2005

"Ken" <lerameur@sdom.com> wrote in message
news:K5btf.6401$l87.729761@news20.bellglobal.com...

Maplin do a pair of audio transformers - LT44 & LT77, one is a driver with
single primary/CT - secondary, the other is for O/P, CT - pri' & single LS
impedance secondary.

c a l a n d e · Dec 31, 2005

Ken wrote:

Ken,

I buy, refurbish and resell these Radio Shack kits. I have a transformer
from an od 65-In-One kit that I'm pretty sure is an exact replacement
for the one you need.

If you're interested I'd be glad to send it to you for $2.00.

Ray Calande

Remove the 86 to reply.

UFO Joe · Dec 31, 2005

I've got tons of those kits, going back 30 years.
I'm an amateur, but if I can help you...

Radio Shack used to sell them separately.

(We lost our Radio Shacks here in Canada - the Colonies - they were bought
out by some oversized American Crap company - Circuit City - now they're
into going for the big bucks
with Big Screen TVs and such, anyhow, forgive me, I digress.)

Radio Shack used to sell them as "Miniature Audio Transformers" if that is
any help.

The numbers on the board are the resistance, 900 Ohms in and 8 Ohms out
(Most speakers are 4-9 Ohms)

I really hope this helps you to find a suitable replacement.

"Ken" <lerameur@sdom.com> wrote in message
news:K5btf.6401$l87.729761@news20.bellglobal.com...

Ken · Dec 31, 2005

Well you are right, Radio shack 200 in 1 kit.
supplied by a max of 9volts

Ken

And that you for all the help.

Ken · Dec 31, 2005

Because I do not have all the working parts. I decided to simulate this
circuit in pspice. I wanted to add this part the circuit. ( I only worked
with very simple circuit using a simulator,..capacitor resistor) there are
many to chosse from also , I wanted to add a transistor A733, there is none
in the simulator, how do I go about chooosing out of the 100 shown in the
simulator ??

thank you

Ken

Jim Thompson · Dec 31, 2005

On Sat, 31 Dec 2005 16:45:26 +0100, "Ken" <lerameur@sdom.com> wrote:

480)460-2350 | |
| E-mail Address at Website Fax

Robert Baer · Jan 1, 2006

Ken wrote:

output (to drive speaker or headphone) connects to the output push-pull
stage of an audio amplifier (or that part of a radio).

safemale · Mar 20, 2006

rat shack used to have them
i think
ham friend used them in the mic line of his home made rig blaster
sound card radio interface
safemale
On Fri, 30 Dec 2005 09:18:42 -0800, Don Bowey <dbowey@comcast.net>
wrote:

Sep 3, 2013

On Friday, December 30, 2005 3:03:30 AM UTC-5, Ken wrote:

(old thread, but appropriately related, I think...)

A number of the radio shack science fair kits (at least 150-1, 160-1, 200-1) and some other equivalents (at least of the 200-1) have a (second) transformer with the labels 4K on one leg of a center-tapped side and 2K on the other (not center-tapped) side. It also has the label "input transformer".

Suggestions for a (hopefully inexpensive) reasonable match/replacement for this part, that is readily purchased somewhere greatly appreciated?

Thanks.

Michael Black · Sep 9, 2013

On Tue, 3 Sep 2013, learntrade@yahoo.com wrote:

If you have to ask a quesiton, then post away. Dont' tack it onto an old
thread, especially not when the problem is that google hasn't fixed the
interface to not allow postings to threads older than 30 days. The rest
of us don't see the thread on some webpage, the old messages are long in
the past.

YOu haven't added anything to the old thread, and the old thread didn't
need any addtions. You cant' justify why you replied to that old post,
you just think it's appropriate.

I thought this was a web type habit, that it was acceptable in the web
forum world. Yet I saw a message on one of the so many web forums that
people have moved to instead of good old usenet, and it was about how
there's no need to resurrect an old thread.

Michael

Oct 12, 2014

On Friday, 30 December 2005 08:03:30 UTC, Ken wrote:

Dear Ken

The Eagle LT700 audio output transformer will be a close match to what you require. Maplin Electronics still have them, or else try Rapid Electronics www.rapidonline.com or jabdog in the UK. Try Circuit Exchange International www.zen22142.zen.co.uk for more component suppliers.

Robert N

Michael A. Terrell · Oct 13, 2014

kaferbug357@gmail.com wrote:

Do you think the OP waited almost nine years for your reply, or is
this just more lame spamming?

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

Radio shack Kit Question on transformer

Ken

Guest

Don Bowey

Guest

DaveM

Guest

Jasen Betts

Guest

ian.field1

Guest

c a l a n d e

Guest

UFO Joe

Guest

Ken

Guest

Ken

Guest

Jim Thompson

Guest

Robert Baer

Guest

safemale

Guest

Guest

Michael Black

Guest

Guest

Michael A. Terrell

Guest

Welcome to EDABoard.com

Sponsor

Online statistics

Forum statistics

Radio shack Kit Question on transformer

Ken

Guest

Don Bowey

Guest

DaveM

Guest

Jasen Betts

Guest

ian.field1

Guest

c a l a n d e

Guest

UFO Joe

Guest

Ken

Guest

Ken

Guest

Jim Thompson

Guest

Robert Baer

Guest

safemale

Guest

Guest

Michael Black

Guest

Guest

Michael A. Terrell

Guest

Log in

Welcome to EDABoard.com

Sponsor