Search found 53 matches

by joe36
Sun Jun 06, 2021 5:41 am
Forum: Troubleshooting Help
Topic: Antenna cable
Replies: 2
Views: 200

Re: Antenna cable

yes, it is what most use. It will work well to several GHZ.
by joe36
Fri May 14, 2021 2:09 pm
Forum: RTL-SDR Discussion
Topic: RTL Dongle - Stock Antenna
Replies: 8
Views: 10353

Re: RTL Dongle - Stock Antenna

I think I might have been mis understood. I was not suggesting splicing coax. I was suggesting that a dipole antenna can be built by separating the center connector from the shield then ataching equal lengths of wire to both the shield and center conductor. A cheap connector, a couple of binding pos...
by joe36
Wed May 05, 2021 9:42 pm
Forum: Antennas
Topic: Android FM Radio Antenna
Replies: 2
Views: 529

Re: Android FM Radio Antenna

I would first call into question the car antenna. I suspect the center were of the coax is coming in contact with DC ground. Test the continuity of the center pin of the SMA to ground. If it is not at ground potential, check continuity of the center SMA pin to the outside antenna. The DC block and F...
by joe36
Wed May 05, 2021 9:08 pm
Forum: Troubleshooting Help
Topic: what do these antennas do?
Replies: 1
Views: 444

Re: what do these antennas do?

The 2 antennas with the coil in the middle are fixed frequency. The telescopic antenna can be use in the shortest collapsed configuration for higher frequencies. Say it is 8 inches long collapsed. The resonate 1/4 wave frequency would be around 300 MHZ extended to say 3 foot it would be resonant at ...
by joe36
Wed Mar 31, 2021 12:12 am
Forum: RTL-SDR Discussion
Topic: GEOS Software Question?
Replies: 3
Views: 727

Re: GEOS Software Question?

With the amplifier placed close to the antenna, using a reasonably low loss coax such as rg6. A very long way, several hundred foot. The amplifier gain will exceed the coaxial loss for at least that distance. In a perfect world the amplifier would provide just enough gain to overcome loses, 0Db at t...
by joe36
Sat Mar 27, 2021 11:23 pm
Forum: Antennas
Topic: UHF (SO-239) antenna bases?
Replies: 6
Views: 1404

Re: UHF (SO-239) antenna bases?

A dipole ½ wavelength has around 3db over A 1/4 wave monopole worked against a ½ wave diameter conductive disk. This is due to the radiation pattern of a dipole being a figure 8 and a 1/4 worked against a conductive surface. This gives no account to conductor diameter or velocity factor. Something t...
by joe36
Sat Mar 27, 2021 7:21 am
Forum: Antennas
Topic: UHF (SO-239) antenna bases?
Replies: 6
Views: 1404

Re: UHF (SO-239) antenna bases?

I think you misunderstood my post. Or I misunderstood yours? “Antenna efficiency meaning how much power of a signal is received and converted into a signal for your receiver is not the same as impedance match”. At 50Mhz a whip style antenna 82" long worked against ground has a radiation resistance o...
by joe36
Tue Mar 23, 2021 2:28 pm
Forum: Antennas
Topic: UHF (SO-239) antenna bases?
Replies: 6
Views: 1404

Re: UHF (SO-239) antenna bases?

You DO NOT WANT! The magnetic mount. It will not work for this application. Do you have a railing with vertical supports? If so you might be able to use hose clamps to hold it on. The Discone antenna is a very good choice for a wide frequency range. The type of antenna you have purchased. The diamon...
by joe36
Sun Mar 21, 2021 1:23 am
Forum: Antennas
Topic: Question about this Mini-Whip
Replies: 2
Views: 610

Re: Question about this Mini-Whip

yes

joe
by joe36
Fri Mar 19, 2021 9:55 am
Forum: Antennas
Topic: Test antenna
Replies: 10
Views: 1884

Re: Test antenna

I must apologies for the type O it was suppose to be a capital I. As with tonight. I was typing in the dark. With a bit of insomnia. YES I use and highly recommend RG6 coax. There are some very small diameter coax good for moderate lengths at HF and below They are usually have high loss. Unless it i...