Re: [Discuss-gnuradio] TVRX / pigtail impedance

[Sylvain Munaut]

>> I recently acquired a USRP with a TVRX. In the package there was also a
>> F -> SMA pigtail to put in the front.
>>
>> But that kinda surprised me from an impedance point of view because:
>>  - The TVRX input is 75ohm according
>>  - F connector is 75 ohm afaik.
>>  - The RG316 cable used for the pigtail is 50ohm
>>  - SMA is 50 ohm afaik.
>>
>> So that looks like a weird mix.
> 
> Yes, it is a weird mix.  But it doesn't really make any difference for
> that short piece of coax at these frequencies.  If you really want, you
> could get a 50 ohm to 75 ohm transformer and then just use SMAs.

Ok, and should I consider the SMA input to be 50 or 75 ohm ?
(so If I make an antenna, is it better to make a 50 or 75 ohm to input
it in the SMA ? or maybe it doesn't matter either ?)


Sylvain