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Monday, January 13, 2003
LoJack leads LAPD Air 8 to stolen vehicle [Source: Freq Of Nature] UPDATE: Recording of a short LAPD pursuit after Air 8 located a stolen vehicle with LoJack. This was recorded with a Uniden BC250D APCO-25 compatible digital radio scanner. Sunday, January 12, 2003
Uniden BC250D Power Reqirements Bench Test [Source: Sly, DIGITAL-SCANNING Yahoo! Group] (Originally posted to the DIGITAL-SCANNING Yahoo! Group)  With all the hoopla about the battery/charging and such I thought I'd do some tests on the radio and pack to see what the radio and pack is drawing from the wall wart and what the radio draws form the pack. I used a Fluke 77 DVM and various jumpers when needed.1. For the first test I disconnected the battery from the radio and see what the radio is drawing by itself from the wall wart (a 500ma 12vt supply). This is with the digital card installed and enabled in the menu. A) Radio draws 199ma squelched, no signal present, tuned to a blank (000.0000) channel, no backlight. B) Interestingly radio draws slightly less, around 192ma when tuned to an actual freq, squelched, no signal present. C) Radio with signal present (such as NOAA) and med volume (2 o'clock position) runs around 200-210ma. D) Radio with signal present Full Volume (NOAA) around 260ma and 340ma tuned to a moto data channel full volume E) Backlight adds an additional 24ma (med) and 53ma (high) F) Another interesting observation is the radio draws 12ma from the wall wart when turned off and no bat pack inserted. (also see 4c) 2. Next I removed the digital card to see if it (the card) draws any additional power. A) Yes it does, power requirements went down. The digital card draws an extra 75ma just being in the radio and enabled (with radio on). Regardless if digital is being received or not. B) Next I re-inserted the card and merely disabled it thru the menu so see what that did. Power requirements stayed down as if the card was not inserted. So in a nutshell if you want the longer battery life and you don't need digital capabilities at the moment then disable the card thru the menu. 3. Next I wanted to see what the power requirements were with a dead battery inserted in the radio both on and off. A) With radio off it draws 178ma with a dead battery inserted. B) With radio on, it draws 360ma with no signal present and digital card on. C) I did not test it in addtion with volume at full level. I figured one could extrapolate this from this test and the first tests above. Anyway I see the need for the 500ma wall wart. 4. Next I wanted to see what the radio draws from the bat pack alone-no ext power and with the digital card on. This test may not be very accurate as to the "jerry rigging" of connectors and jumpers needed. But it should be close enough to get an idea. A) Radio (turned on) draws approx 200ma from the pack, no signal present, digital card enabled. B) With the digital card turned off it draws 120-130ma. So about a 75mah savings with the card off. C) Regarding (1f) no power is drawn from the bat pack when off. So apparently just when its hooked to the wall wart. 5. Last test I wanted to know what amount of ma is the pack drawing from the radio while charging. This test may not be very accurate as to the "jerry rigging" of connectors and jumpers needed. But it should be close enough to get an idea. A) For a dead pack in the radio, radio off, it draws 130ma from the radio. If you'll see the test above (3a) the radio draws 178ma from the wall wart with the radio off and a dead pack inserted. Not sure where the extra juice is going B) I have not tested (yet) to see what the ma drops to after the pack has had significant time to charge. But will prob later. hope this has been of value, Sly N5GQB |