Batboard

although not entirely new to motorola products, I am a newbi on mot 2-way stuff. I want to make a portable repeater utilizing two sabers. But thats not the problem.
The problem is I have radio (s) that are securenet S (whatever the s means) and there is no module installed. How can I make a bypass module so the radio will transmit audio ? (ya see thats the prob. no audio on Xmit due to no module installed)

Check your private messages.

Frank
10-95

can you share the trick with me too?

thx.

Hi:

<b>No real secret !!</b>

All the By-Pass module U900 is a jumper
between Pin 1 and Pin 17 in the following:

<img src="http://www2.4dcomm.com/metrotech/u900_1.jpg">

I generally use the wire from a Small Diode, and just bend the wire over to fit. Its
recommended to use a small piece of Teflon Tubbing to prevent any shorts

Monty



<font size=-1>[ This Message was edited by: [email protected] on 2002-02-28 00:17 ]</font>

On 2002-02-27 23:32, [email protected] wrote:
Hi:

<b>No real secret !!</b>

All the By-Pass module U900 is a jumper
between Pin 1 and Pin 17 in the following:

<img src="http://www2.4dcomm.com/metrotech/u900_1.jpg">

I generally use the wire from a Small Diode, and just bend the wire over to fit. Its
recommended to use a small piece of Teflon Tubbing to prevent any shorts

Monty

<font size=-1>[ This Message was edited by: [email protected] on 2002-02-28 00:17 ]</font>

Hi Monty.

I had done so a few times, but found out, that an unshielded wire causes problems (squealing noise) with rf in tx-mode on some radios. It seems, the wire acts like an small antenna. With an shielded wire (shield connected to GND) or the original bypass, the problem was gone.

Keygun

So what pins are gnd in the socket ?
Thanks
Chris

Hi:

As there may be a " Exception " to any radio,
out of the 100's I have done, I have never
experinced the problem.

Inside U900 is nothing more than a simple
Wire bridged accross a Plastic Strip holding
the pins in place. Although there is a Shield
that holds the plastic strip in place, it still would be subjected to RF.....

If that was a problem in a paticular radio, one can use some " Mini-Coax" strip off the ends, and add a ground connection ( however if you look at the diagram of U900, there is
no ground connection being made other than
a tab, but the Plastic holds nothing more
than the shorting bridge, and has a shield
cover. I susepct they use the " Dummy " module to charge more and the modules look
exactly the same except for whats inside...

A simple Wire in the Motorola Commerical World would look tacky and cost 25.00-50.00

Squeeling in a Saber can be traced many times
to " by-Pass" caps along the DC Line....They
break all the time causing all kinds of unique problems.

Usually happens when the radio gets dropped a number of times.

Perhaps other members will toss there comments in. All Welcome.

Monty

<font size=-1>[ This Message was edited by: [email protected] on 2002-02-28 09:28 ]</font>

When I opened my secure capable Saber (after using it for a few years) found the jumper
inside the radio was a 'twist tie' with the
ends stripped- guess a down and dirty way of
making up a insulated jumper.

Pin 12 looks suspiciously like GND. Its connected solid to the plane in the picture.

On 2002-02-28 05:17, hycheng wrote:
So what pins are gnd in the socket ?
Thanks
Chris

PIN 12 and PIN 19 are Ground.

Keygun

On 2002-02-28 09:20, [email protected] wrote:
Hi:

As there may be a " Exception " to any radio,
out of the 100's I have done, I have never
experinced the problem.

Inside U900 is nothing more than a simple
Wire bridged accross a Plastic Strip holding
the pins in place. Although there is a Shield
that holds the plastic strip in place, it still would be subjected to RF.....

If that was a problem in a paticular radio, one can use some " Mini-Coax" strip off the ends, and add a ground connection ( however if you look at the diagram of U900, there is
no ground connection being made other than
a tab, but the Plastic holds nothing more
than the shorting bridge, and has a shield
cover. I susepct they use the " Dummy " module to charge more and the modules look
exactly the same except for whats inside...

A simple Wire in the Motorola Commerical World would look tacky and cost 25.00-50.00

Squeeling in a Saber can be traced many times
to " by-Pass" caps along the DC Line....They
break all the time causing all kinds of unique problems.

Usually happens when the radio gets dropped a number of times.

Perhaps other members will toss there comments in. All Welcome.

Monty

<font size=-1>[ This Message was edited by: [email protected] on 2002-02-28 09:28 ]</font>

For some strange reason some of my older NTN4720A bypass-modules have 6 or 7 Pins, the newer ones have only 4 (2 Pins for Ground/Can and 2 for the bridge.

The last time i encountered the mentioned problem on a SABER1 UHF. With simple wire bridge: squealing noise in transmit mode; after shortening the wire to the minimum possible lenght: no problems. Also with the bypass module and a short piece of subminiatur coax.

Keygun

Hi:

To help clarify, the " Shield Housing " for the Encryption Modules is the Same as for the
By-Pass Module.

Most have all the Pins, some don't as they are not used. The Modules can be a little
tough to remove if all the pins are there.


The Exact Same Shield is used on the By-Pass
Module as well as the Active Module. It would
not be Sound to have 2 different types.

However, regardless of how you view it, the
Shorting Wire inside the Module is Mounted on
a Plastic Plate, and from a RF point of view,
the outside cover shield does not provide all
that much protection as it sits a good 1/4 to
1/2" above the Plate where the Interior Shorting wire is placed.

So long as one uses good common sense, keep the Wire as close to the board as possible, you should have no problems.

In fact, if one uses the Shorting wire method,its actually closer to the Board to
minimize the RF from travling along the wire,
as a Jumper wire is closer the board via the Module By-Pass method.

This is assumming of course you do not have
a large LOOP of wire going from one pin to the other.

Truly if you have a " unstable " Saber and
I have seen alot of them, you can examine
how the transmitter performs if you have
a Spectrum Display Monitor That is what I use to
find 20 / 30 pf RF-BY-Pass caps that are bad.

RF floats all over the Saber Radios, hence
its jsut good design sense to have all the
Modules ( And PC Board ) Shielded as best
as possible...

If in fact you have a problem saber you
still use mini-Coax and run a wire from the
Shield to ground.

Of course if you can find the By-Pass Module
at a inexpensive price ( I hate the word cheap ) by all means use the module as the module would not have a tendency of getting loose.

Monty



<font size=-1>[ This Message was edited by: [email protected] on 2002-02-28 20:07 ]</font>

Ok, anyone know how to bypass in the same or similar fashion for a Spectra secure socket and a MTS2000 secure socket?

how are you going to make a repeater out of two sabers ????

well let me start out with method 1: this would be by using two converacoms for saber. I believe these boxes have some kind of signal out when the aquelch opens. I KNOW the ht1000 MTVA (convertacom) does. I sue my mts2000 in it all the time with the pac-rt switch activating the controller to an external radio. I think you can even buy Genuine motorola parts to do this kind of setup.

Method2: (and this is what i am Actually going to do.) Is to take one of those nice shiney new aluminum mini briefcases, and mount the two or probably 3 sabers in there with a cell phone patch and possibly an additional 800Mhz receiver so that i can remotely control it with my motorola startac(flipphone) and the local 800 repeater. Motorola stuff is Cool. Way better than those other welfare radios.

Does the radio need to be retuned again (squelch adjusted etc...). After pulling a des module out and replacing it with a jumper....the squelch is messed up (breaks easily) and the received audio sounds odd..

Hi:

Removing or re-installing the Encryption
Modules does not really require realighnment.

Chances are pretty high that your squelch
sensitivity may have been just on a threshold
soft pot value, and if you are in a carrier
squelch mode, you can run into all kinds
of minor problems....your radio could be
responding to a low level signal or similar.

Its pretty easy just to increase the carrier
squelch sot pot value by 4-5 points, and it will not have a major impact on the receive
performance.

Monty

actually with the module in place it receives great....with the jumper across it sounds horrible....it fades in and out and the audio sounds like crap. Something is going on here more then just a squelch problem. Ideas? Thanks.

OK. since the pic provided is UPSIDE DOWN,

Here is what the pins look like from the TOPSIDE
where the module plugs in.


15 14 13 12 11 10 09 08 07 06 05 04 03 02 01

16 17 18 ---------------------------19 20

and yes it is pins 17 and 1.

Heh- This should help a LOT.

I'm wondering why there are two kinds of modules, one which is plastic and the other which is a can. Could it be that Motorola discovered at some point that the can works better than the plastic piece? I have VHF and UHF Securenet Sabers, both of which use the plastic module and neither has any obvious problems.