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#11
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Portable/back up transceiver
"jan olieslagers" wrote in message
... Of course NiMH have better capacity, but Murphy says they'll be full anytime anyway, except when you need them. That's why I don't particularly like rechargeables of any type for emergency use. A good fresh set of non-rechargeable alkalines will give you about 5 years of shelf life depending on how they are stored and lithium batteries will last a bit longer. The manufacturers sometimes spec 10 years or more on lithiums, but you're getting down to 50-70% of capacity at that point which is not exactly what I'd like to be thinking about in IMC. Most of the portable transceivers have battery pack options that allow you to use alkaline or lithium batteries along with rechargeables. It's very nice to have both packs so you can swap them around when you're using the transceiver for non-emergency uses. |
#12
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Portable/back up transceiver
Enough about batteries. Want portable/back up comm recommendations -
Icom, Sporty's etc? Have portable GPS, so Nav is not that important. |
#13
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Portable/back up transceiver
On Jul 27, 9:32*pm, bobengr wrote:
Enough about batteries. *Want portable/back up comm recommendations - Icom, Sporty's etc? *Have portable GPS, so Nav is not that important. You can't go wrong with Icom. I have had an A2 for over 20 years, and have had no trouble (other than batteries). Don't waste your money on an optional Nav function. Regarding batteries, I use alkalines exclusively. Rechargeables need to be cycled regularly (run down then charged up) to be dependable. The batteries in a backup tranceiver tend to see only very occasional use (with long periods of neglect in between). Alkalines have an excellent shelf life. The only downside is that they have a higher internal resistance, and don't put out current as well as the others. That translates into "use low power on transmit unless absolutely necessary to use high power". Dave |
#14
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Portable/back up transceiver
bobengr wrote:
Looking to buy a protable/backup transceiver. Any recommendations? If you get one, you better buy the headset adapter. Otherwise they are almost worthless in the cabin, due to noise. I found that out and quickly bought the adapter. I also have a ICOM and liked. Makes a nice scanner also. Mine did not have the nav function. -- Regards, Ross C-172F 180HP Sold KSWI |
#15
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Portable/back up transceiver
jan olieslagers wrote:
Steve Hix schreef: In article , bobengr wrote: Looking to buy a protable/backup transceiver. Any recommendations? I've got an Icom IC-A6 that's pretty nice. Same here. Don't know where you are but here in Continental Europe it's often worth a train ticket to England to buy it there. Typically 400 € vs. 200 GBP. Mind you a true back-up must cover all radio-failures, meaning it should not be powered from the aircraft power bus. But making sure the batteries are fully charged is one more point on the already too long pre-flight checklist. I would not use rechargeable batteries, rather Alkaline batteries instead. -- Regards, Ross C-172F 180HP Sold KSWI |
#16
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Portable/back up transceiver
"Clark" wrote in message Just a data point - I've been using the long-life hybride rechargeables for about a year now and find they give good service. I don't use the older nickle metal hydride rechargeables at all anymore. What is a "hybride" (sic) battery? What color is a nickle? (Green, look it up. It is a woodpecker.) Jim |
#17
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Portable/back up transceiver
"bobengr" wrote in message
... Enough about batteries. Want portable/back up comm recommendations - Icom, Sporty's etc? Have portable GPS, so Nav is not that important. I had a Vertex that failed completely after about 5 years. I now have the Icom A4 and I like it just fine. It's no longer being made, but you can still find them for sale new. It's been replaced by the A14. I think it might have a slightly lower power output than most, but it wasn't enough that I could notice any difference compared to my old Vertex. None of them work very well unless you're reasonably close to the ATC radio anyway, although if you have an externally mounted antenna you can increase your range somewhat. All of them are limited by power output, so most are going to have virtually the same range. |
#18
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Portable/back up transceiver
Given the fact that a 1 watt transmitter on one end and a 1 microvolt
receiver on the other end have a maximum theoretical range of 1800 miles, how in the world can you say that a 4 watt transmitter is "limited by power output"? The limitation is always by line of sight or antenna configuration. Jim "Mike" nospam @ aol.com wrote in message ... .. I think it might have a slightly lower power output than most, but it wasn't enough that I could notice any difference compared to my old Vertex. None of them work very well unless you're reasonably close to the ATC radio anyway, although if you have an externally mounted antenna you can increase your range somewhat. All of them are limited by power output, so most are going to have virtually the same range. |
#19
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Portable/back up transceiver
"RST Engineering - JIm" wrote in message
... Given the fact that a 1 watt transmitter on one end and a 1 microvolt receiver on the other end have a maximum theoretical range of 1800 miles, how in the world can you say that a 4 watt transmitter is "limited by power output"? The limitation is always by line of sight or antenna configuration. Since all transceivers of this type are limited by the FCC in regards to how much power they can output(and most of them develop the max power allowed at about 1.5w nominal) and since all of them come with essentially identical omnidirectional antennas, I can pretty much assume they will all have very similar ranges, since obviously the transmitter is going to be the limiting factor seeing as how the other end is putting out roughly 7db more power. So you can use the opportunity to mentally masturbate your "engineering" knowledge and talk about theoretical true parabolic reflectors and receiver sensitivities that don't even approach practical applications, but you're not really contributing much to the OP's question. |
#20
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Portable/back up transceiver
"Mike" nospam @ aol.com wrote in message
... "RST Engineering - JIm" wrote in message ... Given the fact that a 1 watt transmitter on one end and a 1 microvolt receiver on the other end have a maximum theoretical range of 1800 miles, how in the world can you say that a 4 watt transmitter is "limited by power output"? The limitation is always by line of sight or antenna configuration. Since all transceivers of this type are limited by the FCC in regards to how much power they can output(and most of them develop the max power allowed at about 1.5w nominal) and since all of them come with essentially identical omnidirectional antennas, I can pretty much assume they will all have very similar ranges, since obviously the transmitter is going to be the limiting factor seeing as how the other end is putting out roughly 7db more power. So you can use the opportunity to mentally masturbate your "engineering" knowledge and talk about theoretical true parabolic reflectors and receiver sensitivities that don't even approach practical applications, but you're not really contributing much to the OP's question. I don't always agree with Jim; but he is absolutely right on this one. When I worked as an avionics technicial, most of the problems that I saw were ultimately wiring issues of the coaxial cables (frequently broken at the antenna connector) and only occasionally degraded sensitivity of the receiver. That was long ago, and more modern receivers should suffer far less degradation. The most entertaining case was a Bellanca on which one of the two comm transceivers would successfully receive the tower frequency about 6 miles from the airport and transmit just a little further. It turned out that there was an in-line coax connector which had become disconnected and the radio signals both transmitted and received were only through the braiding of the coax cable! Peter |
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