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#1
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In article , "Anonymous" wrote:
No reason the PLL frequency should change between TX and RX as I'm only using it on FM simplex. Just goes to show that YOU really don't understand the technology that your dealing with...... Maybe a few courses in Modern Radio Design, would help you understand how the PLL System works in an FT480R..... |
#2
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![]() "You" wrote in message ... In article , "Anonymous" wrote: No reason the PLL frequency should change between TX and RX as I'm only using it on FM simplex. Just goes to show that YOU really don't understand the technology that your dealing with...... Maybe a few courses in Modern Radio Design, would help you understand how the PLL System works in an FT480R..... Which bits of it do you say that I don't understand? Loop stability in control systems, perhaps? Lead/Lag compensation? Triple loop PLLs to give 10Hz steps but without the final loop stepping in 10Hz? What exactly? |
#3
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In article , "Anonymous" wrote:
"You" wrote in message ... In article , "Anonymous" wrote: No reason the PLL frequency should change between TX and RX as I'm only using it on FM simplex. Just goes to show that YOU really don't understand the technology that your dealing with...... Maybe a few courses in Modern Radio Design, would help you understand how the PLL System works in an FT480R..... Which bits of it do you say that I don't understand? Loop stability in control systems, perhaps? Lead/Lag compensation? Triple loop PLLs to give 10Hz steps but without the final loop stepping in 10Hz? What exactly? It is the part where the PLL Frequency doesn't change because you at using FM Simplex. There are many reasons for the PLL to change between Tx and Rx, even with the radio in FM Simplex mode. 1. The receiver may have an IF Frequency of 10.7 Mhz which would require the PLL to be offset from the Receive Frequncy by the IF Frequency, 2. The Transmitter exciter may use a different Offset Frequency than the Receiver IF Frequency, and most Transmitters don't modulate the Tx Output Frequency directly, but modulate an IF Frequency that is, either "mixed" to the Tx Frequency, or "multiplied" to the Tx Frequency. Just to name a few. Now Sir please, expound your brilliance on why you made such a Stupid Comment in the Original Post, as sited above........... |
#4
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![]() "You" wrote in message ... It is the part where the PLL Frequency doesn't change because you at using FM Simplex. There are many reasons for the PLL to change between Tx and Rx, even with the radio in FM Simplex mode. 1. The receiver may have an IF Frequency of 10.7 Mhz which would require the PLL to be offset from the Receive Frequncy by the IF Frequency, This is classic radio design, the vast majority of crystal controlled VHF rigs from the seventies and eighties had a separete crystal for TX and RX because of the IF stage in the receiver. Not true of all rigs though. The FDK Multi 2000 as well as a PLL VFO has a number of crystal memories and has a single crystal for each memory, but it's more the exception than the rule - probably done to reduce cost of two crystals rather than one for each channel. |
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