Trial Run Results for Three Types of Whip Antennas

AnirbanSen

New Member
The difference after adding a HDTV amplifier to my existing handy spider. The amplifier requires power from a USB source or 6V via coax:

2884

2885

2886
 

AnirbanSen

New Member
I'm sure aliexpress has some 1090 MHz SAW filters you can buy.
2 SAW filters arrived today. Any tips on how to solder them onto a breadboard/Vero board?
There shall be 2 SMA connectors on each end.

But the filters are really small 4mm x 4mm. Let's hope I can find a semi professional who can actually get this done.

IMG_20190708_164937.jpg
 

ab cd

Senior Member
2 SAW filters arrived today. Any tips on how to solder them onto a breadboard/Vero board?
May be these diagrams will help. Terminal B is input, E is output. Terminals A, C, D & F are ground.

2893


.
2894


 
Last edited:

wiedehopf

New Member
Not sure how you would solder that onto a prototype board while maintaining a proper signal.
Managing high frequency signals on PCBs isn't trivial and to be honest i don't really have a clue about it.

Due to the small pitch you might want to put the chip on its back and solder tiny wires to the terminals.
Google dead-bug style SMD.

So i'll just wish you good luck, too bad your import rules didn't allow you to get the proper filtered LNA :/
 

AnirbanSen

New Member
May be these diagrams will help. Terminal B is input, E is output. Terminals A, C, D & F are ground.

View attachment 2893

.
View attachment 2894

I did come across some of your discussions from 2015. There seems to be some literature that says that the input/output must be orthogonal to each other. Also, the thickness of the board show be around 0.2mm (impossible to find).

Not very sure how it can be implemented but will try and wing it.
 

AnirbanSen

New Member
Not sure how you would solder that onto a prototype board while maintaining a proper signal.
Managing high frequency signals on PCBs isn't trivial and to be honest i don't really have a clue about it.

Due to the small pitch you might want to put the chip on its back and solder tiny wires to the terminals.
Google dead-bug style SMD.

So i'll just wish you good luck, too bad your import rules didn't allow you to get the proper filtered LNA :/
Yeah, I know. The tiniest soldering I've had done is on the 555. This is way smaller. But let's see what happens. Need to find a board with 0.7mm strip width and that is a challenge as well.
 

wiedehopf

New Member
You could just solder it between two pieces of coax without a PCB.

Basically you could fix a length of coax optimally with connectors to a piece of plastic or wood.
Then you just cut the coax open with a disposable blade maybe 2 cm. Just remove the top half so the center conductor is exposed.
Cut the conductor so you have a 1 cm gap.

Then you clue the filter upside down to the coax insulator.
With single strands from braided copper wire you can now connect the terminals appropriately.
Then you use a bit of copper sheet to close the gap in the shield if you want. Or some mesh.

Would probably be better than trying to get the 1090 MHz to play nice and go along PCB traces.
 

AnirbanSen

New Member
Basically you could fix a length of coax optimally with connectors to a piece of plastic or wood.
Then you just cut the coax open with a disposable blade maybe 2 cm. Just remove the top half so the center conductor is exposed.
Cut the conductor so you have a 1 cm gap.

Then you clue the filter upside down to the coax insulator.
With single strands from braided copper wire you can now connect the terminals appropriately.
Then you use a bit of copper sheet to close the gap in the shield if you want. Or some mesh.
So the last 3 hours in making a premature attempt to see if center conduct can be connected directly. Whereas the first connection to the B terminal was successful, it went downhill from there with other terminals' solder bleeding to the adjacent terminal. I will see if someone can just solder copper strands or about 28SWG wire tightly to the terminals. I can carry out rest of the coax surgery.

How important is it that A,C,D and F all need to be connected to the coax shielding cable? The resistance between them is zero so they are internally the same.

See also: https://www.qorvo.com/products/d/da003143 (Page 3) and https://wireless.murata.com/pub/media/products/apnotes/an42.pdf
 
Top