Question 1

Has anyone tried this (with sma-to-f adapters) for tv use?  this would result in 50-ohm to 75-ohm mismatch. hard to find traps for tv use.

Accepted Answer

A 50 to 75 Ohm impedance mismatch is completely negligible on RX, so impedance mismatch won't be an issue.

Question 2

Does this have RG6 cable connections?

Accepted Answer

RG6 is a type of cable, not a connector. But I think you're meaning to ask if it uses F-Type or PAL type TV connectors? No this uses SMA connectors. Please see the product description for more info about the connectors it uses.

Question 3

What is the max RF input of this device?

Accepted Answer

I would recommend no more than 1W (30dBm), but we have reports of users using them long term with power levels of up to 20W (40dBm) without any issues.

Question 4

I am trying to target 108 mhz specifically. is there a schematic if i need to alter something? (of course, voids any returns) maybe from 107 to 109 m

Accepted Answer

Sorry, it wouldn't be practical to try to modify this filter to reject a very small band. Having opened mine, IIRC the filter has only a few sections, 3 or 4, in a pi configuration. That means it only has a handful of pole pairs in its transfer function. As the bandwidth narrows, the number of poles required to achieve the required response increases, pretty much as the inverse of the bandwidth. So for a bandwidth 1/10 as wide as the 20 MHz it's designed for, you might need a filter of roughly 10x complexity, as a starting point. That's not really practical, so the system engineer would probably recommend completely different architectures, such as a lowpass or highpass, which still would be quite difficult and require much higher Q (larger) resonators, such as cavities or exotic materials. The other approach would be a tunable bandpass at the frequency of interest. That's not exactly simple, but it's probably far easier. There may be other system options depending on the separation from 108 MHz, the degree of rejection required, the type of modulation involved, etc.

ASIN	B01LE9LRPM
Analog Video Format	PAL
AntennaDescription	Radio
Brand Name	RTL-SDR Blog
Colour	Black
Compatible Devices	Laptop, Desktop, Radio Scanner
Connectivity Technology	Radio Frequency
Connector Type	SMA
Customer Reviews	4.6 4.6 out of 5 stars (340)
Includes Remote	No
Manufacturer	RTL-SDR Blog
Manufacturer Part Number	4330366327
Model Number	4330366327
Tuner Type	FM
UPC	642419993872

Broadcast FM Block Filter (88 - 108 MHz Block) by RTL-SDR Blog

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