Hi Graham try Rapid Electronics www.rapidelectronics.co.uk part number 67-0886 You will need to check the site because thta is from the 2006 paper cat. They have no min order but charge £3 postage fo
Hi John yes a Coronal hole flow shock at around 1800-2100z period pushed the Kp up to 5 which is enough to give you a display up there. The radio effects will probably not be felt until tomorrow nigh
Hi Dave, yes indeed. There are two main sources of geomagnetic storm "stimulation". The first is the well known Coronal Mass Ejections (CMEs) that emanate from the area of sun-spots and are usually a
Hi Mike I think the data bursts are actually probably from Lakihegy (Budapest) 135.5 or thereabouts, which is very strong at night and shifts "into" the band a couple of hundred Hz. Loran from Rugby
Hi Graham, ah but yes it will!!. The skip you talk about is due to the ground wave fading below the noise qrm at ranges before the skywave starts to come in at good strength. This is well known in th
Hi Andy I never remember hearing anyone detecting a resonance that high. the first is about 7.8Hz (from memory) and there are "harmonics" at approx 8Hz intervals....only they are not exact multiples,
Thats what the one and a half stop bits are for !! and dating from the days of mechanical serial to parallel converters "clocked" by DC motors with centrifugal governors. Cheers Alan G3NYK
Well the thermo RF current meters measure RMS current, but have you looked at the current from the PSU on a scope?? It shouldn't vary much if the choke is doing its job properly. The FET switches the
Hi Jim I would like to add it to your other articles on my web site if you are in agreement? That is when I get my FTP program sorted out again ! Cheers Alan G3NYK see
Class E ( and I think also probably Class D but I am not sure about that one) will only give maximum efficiency at the design power loading. You cannot tune for max smoke (well you can if you have di
Hi Graham, I think if you are hoping to get a handle on the effect of an elevated loading coil you are in for a disappointment, you can calculate the (small) increase in Rrad this gives. The problem
Hi Jim, that is a very interesting comparison. I estimated the effective height of my inverted L by extrapolating Dick's (PA0SE) field strength measurements for DCF39 and got a figure of 6m for my 9m
Hi Ken then you may need either a transformer or a switching stage that will drive move that 6 to 8 volts on to the gate and handle the high gate capacitance. There is not much point I believe in try
Hi Ken I suggest you are probably not driving it hard enough. Many of these switching FETs require more than 6 volts to swich on hard and they have a very high gate capacity so you need some current
Hi Jim, I wondered whether that was your objective with the "portable site". That is a very interesting confirmation of some of the "thinks" a lot of us have had about ERP calculation and the environ
Hi Vernon this might tend to prove that the simulation is not modelling the travelling wave effect that gives the long low wire is directional preferences (??) Alan G3NYK on the whole 1000' is N/S
Hi Rik isn't it more likely to be the case that these low antennas are much more dependent on ground conditions, which are not modelled very well (or at all) in any of the simulators. In many cases t
