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MaxPro 3000 Plus
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stylzmovement
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Post MaxPro 3000 Plus Reply with quote
I Have an issue with the Max Pro 3000 Plus
Version1.1, firmware 2.0 7/09
Band Selected 88- 108MHz

first i must say the unit runs very cool, the output is also very stable at the given output.
here`s my issue i will get an output of 10 to 12 watts at low frequencies (88 to 93.1MHz , the same foe frequencies above 106.5 to 108 MHz

Between 93.1 to 106.5 the output will be lower than 6 watts on some frequencies but higher that 8 watts

Supply Voltage 13.80 V DC
Available Amperage 4.00 A DC

it would have been good if you to include a section of the Max pro3000 manual talking or showing how to connect the swr pickup point , so can you also address this here.

Thank you...
Fri Jan 29, 2010 4:54 am View user's profile Send private message
pcs
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Post Reply with quote
Does your power supply voltage drop when loaded?

How is your SWR? Note transmitter can drop down power
when high SWR is detected. A photo would be nice.

Marko

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Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Fri Jan 29, 2010 7:22 pm View user's profile Send private message Visit poster's website
stylzmovement
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i will check the voltage at the various frequencies, i will do that within the next few days.

the unit in question is already in service , it is on 107.1 MHz ruining well , but i will do some more test at the various frequencies, then let you know.

as for the swr , i got the results with the unit connected to a dummy load.
the setup was : Max Pro 3000 connected to a 60 watts / 15 volts power supply, with the rf output into a bird 43 watt meter then to a dummy load.

i will also send you some photos of the unit ... in operation.


what about the question i ask about , a section of the manual to deal with the connection of the swr pickup point on the final output . i search your web site for info about the wiring for devices , but nothing was found.
Sat Jan 30, 2010 9:18 am View user's profile Send private message
pcs
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Post Reply with quote
Well if you use our ControlMini board you just plugin flat cable and it is done.
For others there are two solder pads, one for power signal and the other for
swr signal. Connect those two (and ground of course) to your directional coupler
of choice and you are done.

I will add this to the manual in next revision. Any other comments on the
manual can be posted under the manual entry here:

http://www.pcs-electronics.com/phpBB2/viewtopic.php?t=2204

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Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Sat Jan 30, 2010 10:58 am View user's profile Send private message Visit poster's website
stylzmovement
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do you have a manual or any document available for the control mini 1 and 2 ?

i search but did not find any so far.
Mon Feb 01, 2010 5:00 pm View user's profile Send private message
pcs
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Post Reply with quote
They are described in the manual for MAX PRO 3000+.

Marko

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Marko - PCS Electronics
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fax +386 4 2316 128
Mon Feb 01, 2010 5:05 pm View user's profile Send private message Visit poster's website
stylzmovement
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Mon Feb 01, 2010 8:31 pm View user's profile Send private message
pcs
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Post Reply with quote
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.

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Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Mon Feb 01, 2010 11:21 pm View user's profile Send private message Visit poster's website
stylzmovement
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pcs wrote:
Does your power supply voltage drop when loaded?

How is your SWR? Note transmitter can drop down power
when high SWR is detected. A photo would be nice.

Marko



OK, here`s you answer, i tested the exciter without the final amp in the chain , the voltage is constant.

then i tested the exciter with the final amp connected to the exciter , the voltage is also constant, it did not drop from 13.8 V dc,
but still the RF out put varies on the output, it is mostly affected near 98 MHz, that`s where the output will fall to 6 watts maximum
Tue Feb 02, 2010 5:04 pm View user's profile Send private message
stylzmovement
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pcs wrote:
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.



what`s the pro of doing this?
Tue Feb 02, 2010 5:05 pm View user's profile Send private message
pcs
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Post Reply with quote
stylzmovement wrote:
pcs wrote:
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.



what`s the pro of doing this?


Not sure if you had a look at latest manual, but it explains it there. In short, the input impedance of amplifier varies widely across the band and is typically far from 50 ohms resistive at least in parts of the band. This can even trigger SWR protection into reducing output power. Another problem is potential instability under high SWR situations.
One way to cure this problem is to use an attenuator. Attenuator equalizes mismatch between stages and brings impedances closer to prescribed 50 ohms. In pro gear you often find them between stages. To make an attenuator (PI is the type you want to use here) you just need 3 resistors.

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Tue Feb 02, 2010 5:19 pm View user's profile Send private message Visit poster's website
stylzmovement
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Post Reply with quote
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Last edited by stylzmovement on Wed Feb 03, 2010 3:38 am; edited 2 times in total
Wed Feb 03, 2010 3:35 am View user's profile Send private message
stylzmovement
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Post Reply with quote
pcs wrote:
stylzmovement wrote:
pcs wrote:
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.



what`s the pro of doing this?


Not sure if you had a look at latest manual, but it explains it there. In short, the input impedance of amplifier varies widely across the band and is typically far from 50 ohms resistive at least in parts of the band. This can even trigger SWR protection into reducing output power. Another problem is potential instability under high SWR situations.
One way to cure this problem is to use an attenuator. Attenuator equalizes mismatch between stages and brings impedances closer to prescribed 50 ohms. In pro gear you often find them between stages. To make an attenuator (PI is the type you want to use here) you just need 3 resistors.



i saw in other products they use a rf limiter between the exciter and the pre drive amp , that will then drive the final amp.

please bear in mind this issue is happening without an amp connected also , so a mismatch load is not an issue, i have a very good dummy load and for most frequencies it is fairly flat, if you have a circuit that will cure the problem , please tell me about it also can you share some diagrams .
Wed Feb 03, 2010 3:37 am View user's profile Send private message
stylzmovement
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Post Reply with quote
pcs wrote:
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.



do you make or sell a RF attenuator that will pass 10 to 12 watts on the output, the drive required is 12 watts.
Wed Feb 03, 2010 9:01 pm View user's profile Send private message
pcs
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Post Reply with quote
The downside of attenuator is that you get less out than you put in.

So If you put in 12W you get out less, the mode dB of atenuation the
less power you get and the better matching equalization is.

You can make one yourself, easily. The diagram should be in the manual
for MAX PRO 3000+.

By the way, the pallet i see on that photo needs about 5-7W of drive only,
not 12W.

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Wed Feb 03, 2010 11:16 pm View user's profile Send private message Visit poster's website
pcs
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Post Reply with quote
Some comments regarding your case:

1.) The exciter and 700W pallet should be in separate compartments, separated by metal wall.

2.) Power supply should also be in separate compartment. Most power supplies have problem with strong RF from the pallet and it can result in reduced output voltage although the supply is not overloaded at all. It can also result in increased output voltage and death of the mosfets. Oscillations of supply voltage as well.

3.) All points where cables go in/out of the compartment including 700W pallet should be RF blocked or grounded. Especially the 48V supply voltage needs to be RF blocked by bypass capacitors to the ground. Best done with feed-through capacitors or if you can't find them with a few ceramics in parallel, such as 1nF, 10nF, 100nF. Make sure they can take the voltage (use 500V types). Just bypassing the 50V line could be enough, but it is best to do this for all lines. Where you pass coax you can ground its outer sheath to the metal wall.

4.) You may be using them, but just in case I am telling this to everyone, use teflon coaxial cable. Anything else can melt when you solder them to the boards. And if it doesn't melt it can create a short later when things get hot and cheap plastic melts or softens. Use teflon, it can take soldering temperatures without melting.

Hope this helps

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Wed Feb 03, 2010 11:24 pm View user's profile Send private message Visit poster's website
pcs
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Post Reply with quote
stylzmovement wrote:
pcs wrote:
stylzmovement wrote:
pcs wrote:
I recommend you use a small attenuator between exciter and pallet. 1-3dB.
I usually use 1-2dB.

It really helps things.



what`s the pro of doing this?


Not sure if you had a look at latest manual, but it explains it there. In short, the input impedance of amplifier varies widely across the band and is typically far from 50 ohms resistive at least in parts of the band. This can even trigger SWR protection into reducing output power. Another problem is potential instability under high SWR situations.
One way to cure this problem is to use an attenuator. Attenuator equalizes mismatch between stages and brings impedances closer to prescribed 50 ohms. In pro gear you often find them between stages. To make an attenuator (PI is the type you want to use here) you just need 3 resistors.



i saw in other products they use a rf limiter between the exciter and the pre drive amp , that will then drive the final amp.

please bear in mind this issue is happening without an amp connected also , so a mismatch load is not an issue, i have a very good dummy load and for most frequencies it is fairly flat, if you have a circuit that will cure the problem , please tell me about it also can you share some diagrams .


Note that since a few weeks ago MAX PRO 3000+ now has ALC (automatic level control). This lets you limit the power, that is you have a trimmer and you set a power limit where transmitter starts reducing the drive. Works pretty well, we use it in all transmitters.

Regarding drop of power in your unit, I would increase bias current a little with that blue trimmer.

Marko

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Wed Feb 03, 2010 11:28 pm View user's profile Send private message Visit poster's website
pcs
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Post Reply with quote
Since we are discussing MAX PRO 3000+ I just wanted to mention you can now control it via PC:



Probably most of you did not notice the change in the description.

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Thu Feb 04, 2010 12:36 am View user's profile Send private message Visit poster's website
stylzmovement
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Post Reply with quote
what is the required module for the control?
what version of the max pro 3000+ ?

i see you now have the USB IO Board +
and the RS232 IO Board
what is the difference between the both?
do you have the same controls on both?
Thu Apr 01, 2010 4:19 pm View user's profile Send private message
pcs
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Post io board Reply with quote
You need version v2.0, we are selling those since several months now.
And of course the IO board, either RS232 or USB version will be fine.

You simply plug the IO board into the LCD module (there is a 5-pin header there)
and it works.

_________________
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Thu Apr 01, 2010 4:32 pm View user's profile Send private message Visit poster's website
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