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Re: my X6100 test
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Christopher
My point was, irrespective of how low a voltage a radio of any kind can be powered by, there are consequences you have to accept and compensate for, and just because a radio can accept a voltage and available current combination within a nominal range according to specs doesn't guarantee that the spurious emissions levels tested at any given frequency or out of band are parallel across it's entire Tx band spread, and there have been quality radios (IE big money stuff) that have been utterly unclean at under-voltage at the bottom of the acceptable voltage supply range. So whilst, bar impact on Rx performance where is the case, on the Rx side you just live with the impact as a consequence of your actions as usually it only affects you very localised (your reception in other words).? The note of caution was primarily related to on-air activity, IE Tx operation, where running a Tx at extremes of supply range can have scope to cause instabilities and spurious instances that may not necessarily be constrained and preferably nulled by the filters in use. There's no guarantee that at minimum voltage, for example, that any derived sub voltages are clean or as clean as when the main DC power is within a narrow sub tolerance of nominal.? Now given the battery internally acts as a sink, provided the internal battery is functioning and adequately charged currently along with any pre/post regulation, there is a far reduced scope for such problems and then any undue Tx spurious emissions are mostly a consequence of rig design rather than the overall supply chain, as if the true minimum requirement is met, supply wise all is good. But the only way to ensure things are A1 at a given reduced supply is to take actual measurements and also, using correct and accurate service data, test the various stages to see if things are still stable and within tolerance at any given voltage range or point. Usually the emissions compliancy data is based on testing within a sane supply range which is say maybe 10V-14V when the heavier duty? external power is used, and maybe say 7-10V on internal battery power (given some radios do support scope to put a second pack in series internally to up the min/max internal supply availability).? But there's no guarantee at the extremes of supply range that any emissions or stability internally is good, just that the equipment will function within those extremes.? When you talk about Tx capable gear, 'functional' at voltage extremes doesn't necessarily translate into 'still clean' to listed spec re emmisions. Look at service data for any radio, where available, and there's a fairly comprehensive set of tests used to verify the alignment under a range of ideal nominal voltages range within the extremes the equipment was designed to accept. Remember everything is part of a chain in a circuit, where instabilities affect every subsequent sub or connected modular circuit, so anything goes astray early on and it literally has consequences at every stage. I personally don't expect the Tx purity to be that great at min voltage (be it from mostly discharged, just enough current to drive battery state or from external power) as experience with equipment built across my lifetime to date, older equipment, and some pretty cutting edge professional equipment (whose design tolerances and spec? makes ham gear look like toys), and even the best wasn't that pure Tx wise when powered at the lowest voltage it could function as a Tx within shutting down under Tx load. It's just worth taking into consideration and being cautious or at least aware of the potential for - when the equipment is Tx capable that we are, as ham operators, obligated to take into consideration as part of ensuring our stations are meeting EMC requirements as best as feasible whilst not unduly affecting others. On Sun, 26 Mar 2023, 17:23 , <dg1smd@...> wrote: Christopher, |
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