Ive tested dozens of CATV splitters over 25 or so years and they range from falling apart as high as 7-8MHZ and many good to 80 but useless at 160. By good I mean at least a 10dB RL (2:1 VSWR) and 20dB isolation.
For the cost of 3 small ferrite cores, some wire and a resistor its certainly simple to build much better ones. Carl KM1H ----- Original Message ----- From: "Bill Wichers" <[email protected]> To: <[email protected]>; <[email protected]>; "Hardy Landskov" <[email protected]> Sent: Wednesday, August 24, 2011 10:46 AM Subject: Re: Topband: RF attenuators > It would be easy to check if an attenuator is resistive or capacitive by > checking if it will pass any DC. If the attenuator is all resistive you > should be able to measure a low (relatively, i.e. not megohms) > resistance between the ports and between the center pin and ground. > > Regarding the splitters not being useable down low in frequency, I think > I have one of their 10-1000MHz 2-way splitters at home that I can test > down around 1 and 2 MHz easily enough and post the results. > > -Bill > > [snip] >> In general, many VHF/UHF attenuators are built with capacitive > dividers >> rather than resistive dividers, and are unlikely to be useable at HF > and >> below. Conversely, simple resistive attenuators are quite suitable in >> the 2 MHz range, provided that they are made with resistors that are > not >> inductive, whereas their stray L and C would render them useless at >> higher frequencies. >> >> 73, Jim Brown K9YC >> _______________________________________________ >> UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1392 / Virus Database: 1520/3854 - Release Date: 08/24/11 > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
