OK Ken Good luck with the QRO and the key. Just come up on Sunday just let us know you are there. EIRP does help make sure you can run enough power to actually get out on the band irrespective of the antenna efficiency which is bound to be poor on MF /LF. 73 es GL Pete M0FMT IO91 UX
Hi Pete thanks for the additional info, I
had expected to hear from Mal, being an avid cw person, this Sunday is the
Cambridge Group’s Rally at Godmanchester, so I will be going there.
Should not take too long to wind the TX down to 475kHz, the driver is just
adjusting a coil the PA may need additional capacitance, and hopefully it will
still give me 23W into 50 ohms. Then it is back to work on the valve PA, with
about 1500 volts on the anode hope to run about 400W, with about 200W into the
antenna, but with a low radiation resistance it will be well within the 5W EIRP
( whose Idea was it to use that term). Hope to meet you on the Sunday net, hope
the speed is not too fast I have to write cannot do cw in my head.
73
Ken
M0KHW
I have
yet to get my "QRO" 473 rig working but I do still have the 4Watt QRP
Tube / Valve retro rig working on the band just a matter of adjusting the
PA tuning cap ... hee. I want to get my HB Mechanical bug built to go
with.
I have
a Hi Mound side swipe ele key (non Iambic can't remember
the number) mounted on a marble plinth. I am not over keen on the key my self.
Use mainly the good old solid Kent Iambic, mark you it doesn't improve my
sending....... Hee.
Take a
close look at the You Tube film you may find a lot of info there. There is
another film but not as clear on the mechanism.There are other films showing skeleton mechanical keys easier to see and understand,
however the principles are the same. There is even one that does both dits and
dashes fully auto but I bet a nightmare to use since it can't be self
completing so dits could interfere with dashes.
Any way
good luck hope the replies to date have helped. Have you tried
"Fists" yahoo group? These things and very specialised
these days not as easy to use as the ele keyers.
FYI Ken
there is a net on 474 Sunday mornings from about 09:30 out of Biggleswade goes
on for quite a while call ins from Nottingham, Kent etc so please check it out.
73 es
GL Pete M0FMT IO91UX
Thanks for the info, I
was really looking for a single paddle key not a bug but this one came up at a
reasonable price. Should soon be back on LF the new input band pass filter for
the RX pre-amp was completed on Sunday, only problem is that the filter drifts
with temperature,(I never checked this with the 500kHz BP filter), I can
correct for this as there is peaking variable capacitor in the pre-amp which I
use to tune for max signal. All I need to do now is retune the TX driver and
PA, and possibly add a few more turns on the variometer and we should be there.
What I have
been doing over some considerable time is building my own. It's not yet
finished the vibrating part has been mocked up and it will send dits. There is
in fact a lot of clever features you have to think about when designing these
things like after a series if dits you then send a dash the "Reed"
has to be damped to stop it continuing to send a dit. Not only that in transit
the Reed needs a bit of protection so a feature to lock the Reed is desirable
other wise it is continually trying to vibrate as it gets moved or knocked.
This can be achieved by adjusting the damper hard over. Is it the case with
your Key that it has been set for transit.... I don't know this particular Key
but in the You Tube video you can see it operating at the end of the Reed / weight
bar.
Look
forward to hearing it on 630m.
73 es
GL Pete M0FMT IO91UX
I have recently acquired a BK-100 Hi-Mound Bug type Key, although
old, it looks as if it has never been used, the contacts are black, and does
appear to have been set up, and not had any cable connected to it, (I have some
basic set up info from the internet). On inspection it would look as if the
dashes are to the left and dots to the right, is this correct?, there is hardly
any travel on the lever, and vibration on the pendulum. All of the adjustors
seem to be locked. I wpuld be grateful for any help and advice on the operation
and setup of this key.
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