Microwave Forum

imran · Guest

hi
well friend the problem is that i have Max2623 VCO nokia 2110 power amplifier . that eman i guess i have all the parts .just trying to ask u which cricuit will work on these parts.... like i have jammer 1 and jammer 2 cricuit i have cricuit of ur jammer find on some post here... i hope what i mean

and can u plz tell me is this mar-8 peramplifier if yes the where is it in the new cricuit ?

richy_64 · Administrator Messages: 198

Hello,
when you ask me directly which jammer 1 or 2 you can use for your circuit, i have to say: none of them, because you have completely other parts.
In fact, all jammers have the same function, so i also could say: Both.
You can use jammer 2 for inspiration, but you cannot rebuild it with your parts.
It´s the task of the Builder to adapt a circuit of someone else to work with the parts he has.

You use the same parts like me (MAX262x and PF0140), therefore you can look at my test circuit for inspiration.
http://file.carookee.com/forum/broadcasting/1/file/155877/jam.gif

This circuit uses a µC for generating noise, you can also use any other noise generator.
The next step i will do is to insert a preamplifier in the line between vco and power module, because the vco´s output power is too low (this causes the low range of the jammer: just 10 meters). A suitable preamplifier is the MAR-8.
Look at the plan and the picture of kleiner onkels jammer2, you can find them here:
http://file.carookee.com/forum/broadcasting/1/file/198119/Jammer.jpg

http://do4cf.bei.t-online.de/images/rf_jammer_new_version_IMGP6159_2_3.jpg

Yes, it´s the small black spot :-)
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But now i say you (again) what you should do:
Build a small test circuit and learn to modulate the vco correctly with a noise generator (read the postings above). This is the first important step to build a jammer. This is like doing excercises. If you try to rebuild a complete jammer a the first time, you will fail.

greets
Richard

richy_64 · Administrator Messages: 198

Here is an example of a simple noise generator.
The quality of the picture is bad, so here are the parts again:

R1: 10k
R2, R5, R7: 1M
R3, R6, R8: 12k
C1-C5: 1n
D1: 5,6V Zener diode, you can also use a germanium diode like AA11x.
T1-T3: standard npn type, like BC547
Power supply: 9-12V should be fine.

Behind C5 you get a noise signal that is strong enough for our experiments.

The function: Diodes are never completely closed, there is always a little noisy current of some µA (in fact, in most cases this is undisired, but this circuit uses this side-effect).
The transistors T1-T3 amplifier the noise at the cathode of the diode by the factor of 1000000.
[I measured the noise voltage at a germanium diode, a got 10mV with frequencies up to some MHz]

@ imran: You can use this circuit instead of the µC i used.

Richard

richy_64 · Administrator Messages: 198

Here is it:

richy_64 · Administrator Messages: 198

@ imran,
you asked me to explain the used parts of my circuit from above:

http://file.carookee.com/forum/broadcasting/1/file/155877/jam.gif

Nothing special except the µC...?

Linear resistors, the MAX2623, the power module, some transistors? Really usual parts!
Explain me what you don´t understand.

Some additional hints:
On the left side, use the noise generator i posted instead of the µC.
You can input the noise signal at the left side of the linear resistor R8.

You can leave away resistor R3. Just connect Va1 with +5V, too. I found out that R1 is enough for setting bias voltage.
(The bias voltage controls the output power of the power module)

You can leave away T1, because you won´t use the µC (Connect R2 directly with +5V)

R4 sets the oscillator to the frequency range we need (930-950MHz).
The noise modulates the vco, too, so the output frequency of the vco turns randomly around 930MHz (This frequency-noise causes the jamming)
R8 sets the amplitude of the noise signal.

Richard

imran · Guest

hi friend

just need to know the value of the parts
plz if u can and upload any clear pic of PBC of ur jammer it be great help i guess . today i working work with VCO and n-genrator gose welll......

imran · Guest

hi friend
just get one VCO cricuit just wanting u to see and tell me what u think

richy_64 · Administrator Messages: 198

All parts are named except some capacitors, use 10µF ... 47µF for them.
L1 is a choke (or coil, i don´t know the suitable english word), which will not pass through high frequencies. 10 µH or so.

------------------

This may be a spice simulation or similar. Looks like a standard "collector-circuit" (i don´t know the suitable english word again).
I don´t understand it completely. It seems that there are some parasitic parts to simulate the transistor correctly.

------------------
I added the pbc layout of my circuit above. But i think it won´t help you much.

Richard

kleiner-onkel · Administrator Messages: 412 Location: South-West-G

nice work ... @ richy_64

have you shot some pictures of your last jammer based on
AVR signal generator?

how about this broadband VCO ,,, i think the output is not
linear over the entired frequency .... also the matching seems not
possible for this job...

Chris

imran · Guest

hi friends
bcoz of ur help now things r working for me also thx,s
well is there any replcement of MSA0886 . let me know

richy_64 · Administrator Messages: 198

Hello, I´ve found a little crossover list of MMICs.