What TX amplifier do you plan to use?

Quote from DL8SDQ

Has anyone a info about the directional coupler and the output at X102

Hi Jürgen,

usually that is a 40dB coupler...but maybe someone can measure and confirm.

73 de Oscar DJ0MY

I can confirm...

I have now 2x these UMTS working..

First one i damaged the coupler..

But with the second i prepared the the output with additional SMA..

And i use to measure my output for reference..

Be aware, the output can really change if output is not 50Ohms..

I have seen more than 50% difference in output due to bad connectors witch off cause don't show on the referenced output.

Colleagues looking for an inexpensive 23cm amplifier, I started modifying it and something goes wrong.

Quote from SQ8MXL

Colleagues looking for an inexpensive 23cm amplifier, I started modifying it and something goes wrong.

Not sure why you are asking for 23 cm but the eshail is using 13 cm uplink...

Quote from SQ8MXL

Colleagues looking for an inexpensive 23cm amplifier, I started modifying it and something goes wrong.

What would be the max DC input for the UMTS siemens/nokia amplifier.

Currently running on 28V and i know 32 Volt is mentioned but the max ratings of the LDmos are much higher.

I have a 400 watt 35Volt DC supply and i just wonder if the gain and more important the efficiency would benefit from a higher DC input.

Or will i just smoke some parts...

Colleagues looking for an inexpensive 2,4GHz amplifier

Yes, Max voltage for ldmos might be higher but beware voltage on drain is twice the dc voltage in normal Operation when fet is Not conducting- Always keep Supply Volt below half of max drain voltage

Quote from DJ0MY

I am just in preparation of firing up and modifying my Nokia UMTS PA (the one with 2x BLF8G22LS-150) that I've got last year from the source in Poland mentioned here.

In order to get a decent PWR cable connection I just made small PCB adaptors for the 2x5 pin heders (2mm types)...

Since the price was identical for 4 pieces or 20 pieces I ordered 20 pieces - so I have many spare ones now

If someone is interested in a pair of these PCBs for their amp let me know by direct message.

73, Oscar

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Hi Oscar,

can you let me know where i can find these items, i ned two for my PA Nokia UMTS...

TNX. Gio - PA1KEK

Quote from DJ0MY

I am just in preparation of firing up and modifying my Nokia UMTS PA (the one with 2x BLF8G22LS-150) that I've got last year from the source in Poland mentioned here.

In order to get a decent PWR cable connection I just made small PCB adaptors for the 2x5 pin heders (2mm types)...

Since the price was identical for 4 pieces or 20 pieces I ordered 20 pieces - so I have many spare ones now

If someone is interested in a pair of these PCBs for their amp let me know by direct message.

73, Oscar

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Hi Gio,

unfortunately all power connector PCBs are already gone....sorry

73 de Oscar DJ0MY

TNX.

Could please somebody give me some hints where to buy used power supplies, heatsinks, coax cable for the NOKIA PA?

my colleagues once described an amplifier that was to be processed and I have a problem with it because it raises and I do not know how to eliminate it even after the transistors are rescheduled it is still the same maybe you have some advice.

DD8PL have a look to this ebay link:

https://www.ebay.de/itm/2PCS-P…172fc1:g:6acAAOSws8lZz5Dv

he had also 2 or 3 pcs in offers so if you need more for friends you can save S&H.

I use them here already for month.

For now, it didn't help me, I'm waiting for other hints and tips

Mam taki wzmacniacz.

W pobliżu

Hello all

I'm looking to modify the following model which is slightly different than the one shown in the forum, if anyone has any docs on the mods.

thank you in advance

F4FDW Laurent

Hello to the group a question, having made the changes as everyone talks about the UMTS nokia amplifier, today I took it back I did an internal check and I see that I am missing two capacitors I do not know if there was a mistake !!! I have been working for 4 months and everything works smoothly, I ask you have experience I have to add the two condensed what do you recommend thanks.

73 ik1hgi Tony

Hallo,

I am looking for a reliable information which intermodulation distortion can be reached with a Freescale MW7IC2725. My result is approx. 30dBc at 8 to 10 Watts PEP. I don't know if this is the end already. Optimizing the idle current of the two stages does not give a general improvement. Single tone power is not interesting but together with linearity two tone measurement.
Thanks
73

Andreas

Hallo Achim,

I know the datasheet. But are there amateur constructions which confirm this really? Unfortunately nobody does IMD-Measurements. Between my small result and what the datasheet says is a difference. I would like to know where the mistake is. From my point of view, the chip seems to small for 27 Watts SSB-PEP. This means two carrriers with 38 dBm. Does the above diagram show what we call linear operation? More Spacing of the single carriers gives less dissipation. A two tone measurement with the usually small spacing signal from a Pluto or Lime would be appreciated.
73
Andreas