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:
Trial Run Results for Three Types of Whip Antennas
- Thread starter ab cd
- Start date
AnirbanSen
New Member
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.
ab cd
Senior Member
May be these diagrams will help. Terminal B is input, E is output. Terminals A, C, D & F are ground.
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COMPARISON OF 2 VERY SIMILAR 1090 Mhz SAW FILTER CHIPS
Several things you need before starting this challenge: at least 5 hands to hold all the pieces 2 of the hands should be quite small and belong to a surgeon the eyes of an eagle to see the contact patches the patience of a saint I have none of these so don’t critisize my soldering...
discussions.flightaware.com
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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 :/
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
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).May be these diagrams will help. Terminal B is input, E is output. Terminals A, C, D & F are ground.
View attachment 2893
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View attachment 2894
COMPARISON OF 2 VERY SIMILAR 1090 Mhz SAW FILTER CHIPS
Several things you need before starting this challenge: at least 5 hands to hold all the pieces 2 of the hands should be quite small and belong to a surgeon the eyes of an eagle to see the contact patches the patience of a saint I have none of these so don’t critisize my soldering...
Not very sure how it can be implemented but will try and wing it.
AnirbanSen
New Member
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.
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
Very interesting thought. SAW on a coax. Will let you know how it goes. Work beckons. 
AnirbanSen
New Member
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
