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mike65535
mike65535
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I recommend against using the modern inexpensive HT radios for packet, especially if you are buying the equipment on purpose for that application. You'd be much better off with 30 year old-year-old used ham radio mobile gear, with more power, more selective receiver, more predictable operation, easier UI, and less RF into your digital equipment, easier connections, easier power hookup, and nearly the same cost.

A serious consideration with modern HTs is that the designers are interesting in optimizing voice quality and battery life with no consideration for how this impacts packet radio use. Sacrifices can easily be made which increase usability for voice, but which make packet radio work worse and be more difficult to align.

Audio level consistency. A packet radio receiver modem wants to see an audio level that is both consistent across a packet, but also nearly the same for multiple tone frequencies on a packet. FM voice radios don't need to behave in this way. Indeed, voice compression, bad for packet, actually sounds great on voice.

DC signals (BIAS) on the receive audio are also OK for FM voice, especially with built in-in speaker equipment, but this also is of questionable value for a packet radio modem.

POP and CLICK removal: It is easy to remove pops and clicks from the audio by replacing annoying wave forms with duplicates of preceding or following wave forms, or by shifting the time of the wave forms. This is a well documented (and no longer patented) scheme used originally in broadcast radio transmission. This makes the receiver sound much better, at low cost, but makes packets less reliable, and this effect is nearly undetectable without an analog equipped logic analyzer. It's very confusing. I have on low authority that this is done in modern 2-way FM radio-on-a-chip devices.

Battery saving by disabling the radio: By having the control processor leave elements of the radio disabled for periods of time the radio can use less battery power while quiescent, but it would also not be awake to notice the start of a packet message. Baofeng radios are replete with this technology.

The Chinese brand-name radios have been known to emit energy at frequencies outside the ham band at levels beyond those permitted by the various government radio authorities (D.O.C. in Canada, F.C.C. in the USA). They have also been known to emit radio waves at near transmission levels through the chassis which can impact the stability of DC wiring in the vicinity of the radio. This is also confusing to somebody new to integrating digital, audio and RF equipment.

Used 2-way or ham radio equipment is particularly applicable to packet radio. A used ham radio which is missing the critical CTCSS PL TONE generator is nearly useless for repeater operation but is very usable for packet radio. Kenwood TM2550, TM7950, TM7800, are perfectly fine packet radios and are 25 watts output or better. Yeasu Yaesu and Icom have offerings in the same age-class. Because they are not useful to non-packet hams, they show up for low prices, even competitive with brand new Baofeng UV5R radios.

In the commercial 2-way market, the Kenwood TK705d or TK805d is a fine radio for packet. Those are on ebay at under $50 delivered, even as I type. While some commercial 2-way radios need PCs and software to program, the TK705d and TK805d are front panel programmable, or can be made that way by moving or adding a 2-pin jumper.

I recommend against using the modern inexpensive HT radios for packet, especially if you are buying the equipment on purpose for that application. You'd be much better off with 30 year old used ham radio mobile gear, with more power, more selective receiver, more predictable operation, easier UI, and less RF into your digital equipment, easier connections, easier power hookup, and nearly the same cost.

A serious consideration with modern HTs is that the designers are interesting in optimizing voice quality and battery life with no consideration for how this impacts packet radio use. Sacrifices can easily be made which increase usability for voice, but which make packet radio work worse and be more difficult to align.

Audio level consistency. A packet radio receiver modem wants to see an audio level that is both consistent across a packet, but also nearly the same for multiple tone frequencies on a packet. FM voice radios don't need to behave in this way. Indeed, voice compression, bad for packet, actually sounds great on voice.

DC signals (BIAS) on the receive audio are also OK for FM voice, especially with built in speaker equipment, but this also is of questionable value for a packet radio modem.

POP and CLICK removal: It is easy to remove pops and clicks from the audio by replacing annoying wave forms with duplicates of preceding or following wave forms, or by shifting the time of the wave forms. This is a well documented (and no longer patented) scheme used originally in broadcast radio transmission. This makes the receiver sound much better, at low cost, but makes packets less reliable, and this effect is nearly undetectable without an analog equipped logic analyzer. It's very confusing. I have on low authority that this is done in modern 2-way FM radio-on-a-chip devices.

Battery saving by disabling the radio: By having the control processor leave elements of the radio disabled for periods of time the radio can use less battery power while quiescent, but it would also not be awake to notice the start of a packet message. Baofeng radios are replete with this technology.

The Chinese brand-name radios have been known to emit energy at frequencies outside the ham band at levels beyond those permitted by the various government radio authorities (D.O.C. in Canada, F.C.C. in the USA). They have also been known to emit radio waves at near transmission levels through the chassis which can impact the stability of DC wiring in the vicinity of the radio. This is also confusing to somebody new to integrating digital, audio and RF equipment.

Used 2-way or ham radio equipment is particularly applicable to packet radio. A used ham radio which is missing the critical CTCSS PL TONE generator is nearly useless for repeater operation but is very usable for packet radio. Kenwood TM2550, TM7950, TM7800, are perfectly fine packet radios and are 25 watts output or better. Yeasu and Icom have offerings in the same age-class. Because they are not useful to non-packet hams, they show up for low prices, even competitive with brand new Baofeng UV5R radios.

In the commercial 2-way market, the Kenwood TK705d or TK805d is a fine radio for packet. Those are on ebay at under $50 delivered, even as I type. While some commercial 2-way radios need PCs and software to program, the TK705d and TK805d are front panel programmable, or can be made that way by moving or adding a 2-pin jumper.

I recommend against using the modern inexpensive HT radios for packet, especially if you are buying the equipment on purpose for that application. You'd be much better off with 30-year-old used ham radio mobile gear, with more power, more selective receiver, more predictable operation, easier UI, and less RF into your digital equipment, easier connections, easier power hookup, and nearly the same cost.

A serious consideration with modern HTs is that the designers are interesting in optimizing voice quality and battery life with no consideration for how this impacts packet radio use. Sacrifices can easily be made which increase usability for voice, but which make packet radio work worse and be more difficult to align.

Audio level consistency. A packet radio receiver modem wants to see an audio level that is both consistent across a packet, but also nearly the same for multiple tone frequencies on a packet. FM voice radios don't need to behave in this way. Indeed, voice compression, bad for packet, actually sounds great on voice.

DC signals (BIAS) on the receive audio are also OK for FM voice, especially with built-in speaker equipment, but this also is of questionable value for a packet radio modem.

POP and CLICK removal: It is easy to remove pops and clicks from the audio by replacing annoying wave forms with duplicates of preceding or following wave forms, or by shifting the time of the wave forms. This is a well documented (and no longer patented) scheme used originally in broadcast radio transmission. This makes the receiver sound much better, at low cost, but makes packets less reliable, and this effect is nearly undetectable without an analog equipped logic analyzer. It's very confusing. I have on low authority that this is done in modern 2-way FM radio-on-a-chip devices.

Battery saving by disabling the radio: By having the control processor leave elements of the radio disabled for periods of time the radio can use less battery power while quiescent, but it would also not be awake to notice the start of a packet message. Baofeng radios are replete with this technology.

The Chinese brand-name radios have been known to emit energy at frequencies outside the ham band at levels beyond those permitted by the various government radio authorities (D.O.C. in Canada, F.C.C. in the USA). They have also been known to emit radio waves at near transmission levels through the chassis which can impact the stability of DC wiring in the vicinity of the radio. This is also confusing to somebody new to integrating digital, audio and RF equipment.

Used 2-way or ham radio equipment is particularly applicable to packet radio. A used ham radio which is missing the critical CTCSS PL TONE generator is nearly useless for repeater operation but is very usable for packet radio. Kenwood TM2550, TM7950, TM7800, are perfectly fine packet radios and are 25 watts output or better. Yaesu and Icom have offerings in the same age-class. Because they are not useful to non-packet hams, they show up for low prices, even competitive with brand new Baofeng UV5R radios.

In the commercial 2-way market, the Kenwood TK705d or TK805d is a fine radio for packet. Those are on ebay at under $50 delivered, even as I type. While some commercial 2-way radios need PCs and software to program, the TK705d and TK805d are front panel programmable, or can be made that way by moving or adding a 2-pin jumper.

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Tadd KA2DEW
Tadd KA2DEW
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I recommend against using the modern inexpensive HT radios for packet, especially if you are buying the equipment on purpose for that application. You'd be much better off with 30 year old used ham radio mobile gear, with more power, more selective receiver, more predictable operation, easier UI, and less RF into your digital equipment, easier connections, easier power hookup, and nearly the same cost.

A serious consideration with modern HTs is that the designers are interesting in optimizing voice quality and battery life with no consideration for how this impacts packet radio use. Sacrifices can easily be made which increase usability for voice, but which make packet radio work worse and be more difficult to align.

Audio level consistency. A packet radio receiver modem wants to see an audio level that is both consistent across a packet, but also nearly the same for multiple tone frequencies on a packet. FM voice radios don't need to behave in this way. Indeed, voice compression, bad for packet, actually sounds great on voice.

DC signals (BIAS) on the receive audio are also OK for FM voice, especially with built in speaker equipment, but this also is of questionable value for a packet radio modem.

POP and CLICK removal: It is easy to remove pops and clicks from the audio by replacing annoying wave forms with duplicates of preceding or following wave forms, or by shifting the time of the wave forms. This is a well documented (and no longer patented) scheme used originally in broadcast radio transmission. This makes the receiver sound much better, at low cost, but makes packets less reliable, and this effect is nearly undetectable without an analog equipped logic analyzer. It's very confusing. I have on low authority that this is done in modern 2-way FM radio-on-a-chip devices.

Battery saving by disabling the radio: By having the control processor leave elements of the radio disabled for periods of time the radio can use less battery power while quiescent, but it would also not be awake to notice the start of a packet message. Baofeng radios are replete with this technology.

The Chinese brand-name radios have been known to emit energy at frequencies outside the ham band at levels beyond those permitted by the various government radio authorities (D.O.C. in Canada, F.C.C. in the USA). They have also been known to emit radio waves at near transmission levels through the chassis which can impact the stability of DC wiring in the vicinity of the radio. This is also confusing to somebody new to integrating digital, audio and RF equipment.

Used 2-way or ham radio equipment is particularly applicable to packet radio. A used ham radio which is missing the critical CTCSS PL TONE generator is nearly useless for repeater operation but is very usable for packet radio. Kenwood TM2550, TM7950, TM7800, are perfectly fine packet radios and are 25 watts output or better. Yeasu and Icom have offerings in the same age-class. Because they are not useful to non-packet hams, they show up for low prices, even competitive with brand new Baofeng UV5R radios.

In the commercial 2-way market, the Kenwood TK705d or TK805d is a fine radio for packet. Those are on ebay at under $50 delivered, even as I type. While some commercial 2-way radios need PCs and software to program, the TK705d and TK805d are front panel programmable, or can be made that way by moving or adding a 2-pin jumper.