06-09-2020 ISS pass trying the FM repeater.

[@iceman382]

Some ham radios only allow for 5 KHz adjustments in frequency. Therefore, you would listen/receive on the downlink frequency of 437.800 MHz. You can put these seven frequencies in the memory of your radio for fast tuning and easy listening. 437.785, 437.790, 437.795, 437.800, 437.805, 437.810, 437.815 MHz. So by that last example you can see three frequencies below 437.800 MHz ( the downlink frequency), and three frequencies above 437.800 MHz. This will account for the Doppler shift in frequency. PS...The Uplink frequency is shown in the video is 145.990 MHz with a 67Hz tone. That's the transmit frequency from your ham radio to the ISS. Remember, if you are only listening, you only need the downlink frequency of 437.800 MHz. Hope this helps.......

[@DrDiff952]

I have a Baofeng UV-5R I guess I would have to manually switch these frequencies to enjoy a longer connection with the ISS REPEATER

[@iceman382]

AOS stands for Acquisition of Signal (or Satellite). AOS is the time that a satellite rises above the horizon of an observer. That would be 437.815 MHz. LOS stands for Loss of Signal (or Satellite). LOS is the time that a satellite passes below the observer’s horizon. That would be 437.785 MHz.

[@iceman382]

The Doppler effect, or Doppler shift, describes the changes in frequency of any kind of sound or light wave produced by a moving source with respect to an observer. Waves emitted by an object traveling toward an observer get compressed - prompting a higher frequency - as the source approaches the observer. In contrast, waves emitted by a source traveling away from an observer get stretched out. As an example, if a train is approaching straight at you with it's horn blowing, the frequency/pitch of the horn will get higher. When the train passes you with it's horn blowing, the frequency/pitch of the horn will get lower. That's why when listening to the ISS which is in all intense purposes a satellite, the transmitted signal from the onboard ham radio transceiver will change. You would be "receiving" the transmitted signal and it would change frequency slightly, just like the train whistle/horn. So you would adjust your radio slightly higher or lower depending on satellite/ISS position. Some ham radios will automatically adjust for Doppler shift. On others, you would manually make small adjustments.

[@DrDiff952]

I was able to cso off the ISS repeater with a Baofeng UV-5R and Nagoya 771

[@2nomind]

I tried a few times with no luck, but maybe better if the ISS was right over head

[@holgerstraelen8956]

Hi Glenn, it's much easier to use an arrow antenna to make contacts via the ISS or HAM satellites. Good luck! 73 Holger, DK3PA

[@groutdoctor]

I own an duel band Arrow antenna with a duplexer. I wholeheartedly agree.

[@BaDaBoomish]

Which FM-Mode ist more useful for satellite operation? FM-wide (used in older 25-kHz-rigs) or FM-narrow (FMN in TRXs nowadays)?

[@iceman382]

FM wide only.

[@alexdiamantopoulos6614]

Most hand held ham radios on FM bands are narrow.

[@Davidjb37721]

Thanks

[@Davidjb37721]

I’m Confused if you’re going through a repeater why are you using the BFO

[@vk4nga]

Because of the Doppler shift effect (Google it). Cheers Glenn

[@patkilroy9079]

The X-300 vertical antenna has a pretty high gain toward the horizon (and not much above) and therefore will likely work better on the low elevation satellite passes. Continued good luck! DE N8PK-FM19.

[@forgetyourlife]

yep, huge null on the top of that antenna. Those are made for ground stations.

[@SteveWrightNZ]

What is this fascination with leaving the squelch open on FM? Does this add some legitimacy to the activity somehow?

[@vk4nga]

Leaving the squelch open makes it easier to adjust the frequency for the Doppler shift effect.

[@waynethebarber1095]

Hi Steve, let me ask, are you a ham???

[@MirlitronOne]

@@vk4nga ...and optimises sensitivity to weak signals.