[AMRadio] 813 tx


CHRIS PAPAIOANNOU amateur at ipnet.gr
Mon Nov 1 11:57:54 EST 2004


Bob,
i'm surprised  even now while reading these lines of yours..except my test i
mentioned before in my other msge didn't go further on..and of course using
these kind of things like loads depends of the conditions..even if the
output transmitting power is high the dummy radiates a minimal portion of
this power which needs good conditions in order to be heard the max far
away.
73,
Chris,SV1DAF.
----- Original Message -----
From: "Rbethman" <rbethman at comcast.net>
To: "Discussion of AM Radio" <amradio at mailman.qth.net>
Sent: Sunday, October 31, 2004 9:53 PM
Subject: Re: [AMRadio] 813 tx


> Chris,
>
>     I have held QSOs from Columbus, GA to Atlanta on 75 mtrs during the
> daytime with an improperly grounded dummy load.
>
>     You may be REALLY surprised how far you CAN really transmit with
> such things.  It ALL boils down to the CURRENT conditions.
>
> Bob - N0DGN
>
> CHRIS PAPAIOANNOU wrote:
>
> >Jim,
> >I don't think that this bulb dummy load radiated RF far away...but
> >sufficiently far away to provoke the neighbors around to start coming
by...a
> >test once proved me that with a dummy load  my modulation has been heard
no
> >more than about 195 feet.Didn't check out if this distance was more than
195
> >feet because an other fellow ham who was in his house heard me and this
test
> >ended at this point,because this was the object.But since i believe that
> >antennas with regular electrical length depending of the frequency are
> >exactly the opposite of  a dummy load  i guess that this distance
couldn't
> >be a little bit more than these 195 feet.
> >Regarding that Lear T30 seems that the aluminium window frame was a very
> >poor counterpoise..did you use at that time any form of rf ground?
> >I've experienced in the past TVi problems with tube AM rigs due to poor
rf
> >grounds..you can immagine my ma's face when was coming to tell me that
was
> >listening to a strange voice in the tv,something like cat's mew.Then
learned
> >that this was me.
> >Fortunatelly i never had problems with the neighbors.Generally these
> >transmissions were midnight transmissions when the most of them were on
bed.
> >FM?My 1st homebrew rig was a 6BQ5 rig.Self  oscillated (COLPITS type).I
was
> >using an FM receiver when trying to tune it.Had homebrewd a 6AK5(5654W)
self
> >oscillated also.With dipoles on the roof made from aluminium pipe.I
remember
> >that had connected 2 transfrmrs with primaries 220V and secondaries
6,3V/2A
> >secondary to secondary in order to feed the rigs.In this way had no
> >confluences beetween rf and feeding and no hum.
> >Vinyl?I don't need to remember it Jim cause even now i still use my old
> >records..The others here are using digi media.I don't.My amp and tuner
are
> >tube type also.By the others i mean the members of my family.
> >I really enjoyed your memories and experiences Jim,
> >Regards,
> >Chris,SV1DAF.
> >
> >
>
> --
> <                      Bob Bethman - N0DGN
> +-------------------------------+----------------------------------+
> | N0DGN AMRadio Manassas, VA    |    REAL Tube Radio and AM        |
> +-------------------------------+----------------------------------+
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