Jump to content

Leaderboard

Popular Content

Showing content with the highest reputation on 07/09/22 in Posts

  1. That's likely one of the real reasons why it isn't tried. Most of the digital modes have fairly wide signals compared to side band. A SSB signal is around 3KHz, correct, while some of the digital mode signals are like the following examples: 4K00F1E – NXDN 6.25KHz digital voice (IDAS, NEXEDGE) 4K00F1E – dPMR 6.25KHz digital voice (Typically not used in North America, used in the EU) 7K60FXE – 2-slot DMR (Motorola MOTOTRBO) TDMA voice 8K10F1E – P25 Phase 1 C4FM voice 8K30F1E – NXDN 12.5KHz digital voice (Wide DAS, NEXEDGE) 9K36F7W – Yaesu System Fusion C4FM (Voice Wide) 22K0D7E – TETRA DMO Voice Some of those linear translators don't have that much bandwidth to begin with. Using digital isn't going to be welcomed and very highly discouraged, not because it can't be done with the right equipment. As I said before any signal that's transmitted is always an analog type regardless of what information is being sent. The main difference is how the signal is shaped. Simple rectangular pulses are not sent because the bandwidth required is stupid wide. Various types of pulse shaping is used. One such shape is GMSK. There are others with different properties. https://www.oscium.com/sites/default/files/WhitePaper_Simple_Signal_Shaper_GFSK.pdf http://www.sss-mag.com/pdf/gmsk_tut.pdf https://www.researchgate.net/profile/Thierry-Turletti/publication/2575678_GMSK_in_a_nutshell/links/0deec517e72247f39d000000/GMSK-in-a-nutshell.pdf?origin=publication_detail I get the point about possible signal inversion occurring in a linear translator. However that would depend on the design. I would guess not all of then do so. That how the convention between using upper or lower side band on HF originated, selecting the high or low side mixing product of the VFO with the local oscillator depending on the band. Also likely the reason why simply connecting the output from a receiver's discriminator to a transmitter's modulator might not work has to do with the frequency accuracy. With 4FSK it's critical the frequency shifts are right. Being off too much the RX radio can't decode the data. That means the level being fed into the transmitter's modulator has to be very carefully controlled to achieve the expected frequency shifts. That's also assuming the frequency shift is a linear function of the modulation voltage, which it might not be.
    1 point
  2. OffRoaderX

    wide or narrow

    Wider is better.. Unless you plan on using narrowband radios.
    1 point
  3. WQXF313

    Kenwood TK-8360H

    @Radioguy7268 That’s exactly what I needed. Thanks for your help!
    1 point
  4. So, I had fun goofing around today... and the results are a fail (thankfully). All the publicly available tool were a complete failure. This is a very good thing. So, as @OffRoaderX mentioned, short of a hacker compromising the service provider (which is very, very difficult), today no one is grabbing your information from just your IP. Thanks for the friendly challenge Randy!
    1 point
  5. axorlov

    GMRS travel channel

    Leave them alone, the influenzers and their court. People who can read and able to put 2+2 together will find out about 462.675-141.3 very quickly. Those who have youtube-watching gland overdeveloped will congregate on channel nineteen. Win for everybody.
    1 point
  6. jwilkers

    GMRS travel channel

    Actually, there is another channel that has been in place for decades. 462.675 pl 141.3 has been the recognized travel channel for decades. Many repeaters are here, on this frequency/tone. It would have been a good idea to do your homework before all this. All you are doing is creating confusion. Sent from my SM-A125U using Tapatalk
    1 point
  7. kidphc

    GMRS travel channel

    True. It's the ones that don't know about line a and c. Read the internet or watch clips from influencer and are unaware they just violated a international treaty. It is our job as a community to watch out for it as a whole. How many times are the same questions asked? It is the nature of the hobby. Not like gmrs actually requires a test. As someone who use to cross line a to visit in laws on a regular basis pre covid. Thos frequencies are very much in use, by public safety and other services. So it behoofs us to use a frequency that is ok to use for the entire country. Sent from my SM-S901U using Tapatalk
    1 point
  8. H8SPVMT

    GMRS travel channel

    Ya'll go ahead and discuss your silly games. Off Road vehicles already have decided Ch 16 for the call channel.?
    1 point
  9. There are only two GMRS channels that may not be used above Line A: channels 19 and 21. I understand the desire to pay homage to “Channel 19”, but having a “Road Channel” that people within 100 miles of the Canadian border could use, such as the citizens of “Motor City” or Seattle, might be important. The channel 19 touch was a cool idea, though. It’s just better to have a single road channel that anyone can use.
    1 point
  10. I would support the idea if it weren’t for the fact that 10 - 12 million people live far enough north that they are not allowed to use channel 19 because of an agreement with Canada.
    1 point
  11. MichaelLAX

    Btech FRS-B1

    Oh, you’ve become an Online Influencer! ?
    1 point
This leaderboard is set to New York/GMT-04:00
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Guidelines.