[Amps] Dual tetrode in grounded grid

Glen Zook gzook at yahoo.com
Thu Feb 12 23:06:43 PST 2009


Agreed!  But your comment about RG58/U brought it on.  Anyway, enough on the subject.

Glen, K9STH

Website:  http://k9sth.com


--- On Thu, 2/12/09, Carl <km1h at jeremy.mv.com> wrote:

> From: Carl <km1h at jeremy.mv.com>
> Subject: Re: [Amps] Dual tetrode in grounded grid
> To: gzook at yahoo.com, Amps at contesting.com
> Date: Thursday, February 12, 2009, 7:16 PM
> I didnt see anything in all that long winded windup that has
> anything to do with the Amps reflector.
> 
> Carl
> KM1H
> 
> 
> ----- Original Message ----- From: "Glen Zook"
> <gzook at yahoo.com>
> To: <Amps at contesting.com>; "Carl"
> <km1h at jeremy.mv.com>
> Sent: Thursday, February 12, 2009 6:15 PM
> Subject: Re: [Amps] Dual tetrode in grounded grid
> 
> 
> > I am VERY familiar with the characteristics of RG58/U.
>  In fact, I used to buy it by the 1000 foot spools and use
> it for "leaky line" antennas for 960 MHz 47 CFR
> Part 15 installations in places like warehouses and I have
> used it for both highband and UHF installations for paging
> installations in places like hospitals, dropping the line
> down the elevator shafts and running it above suspended
> ceilings.  Frankly, it works at least as good as, and in
> some applications better than, Andrew Radiax which was
> running about $5 per foot versus 10 cents per foot that I
> was purchasing RG58/U for at the time.
> > 
> > I purchase 500 foot spools of RG58/U a couple of times
> a year to use in the interconnect cable kits that I make for
> Collins, Heath, Drake, and other manufacturers.  I
> absolutely refuse to supply used coaxial cables in these
> sets.  Collins specifications call for RG58/U cables, 4 feet
> long, in all the r.f. applications for interconnecting the
> various S-Line units together and the KWM-2 series to
> certain accessory units.  The remaining cables are shielded.
>  Heath uses RG58/U for the antenna connections (RG62/U for
> the BFO, heterodyne oscillator, and LMO connections) and
> shielded cables for the audio and control functions.  Drake
> also uses RG58/U for the antenna connections.
> > 
> > Also, RG58/U is the cable of choice for most mobile
> antenna installations (i.e. supplied by Larsen, MaxRad, and
> so forth).  Of course these applications generally come with
> 17 feet of cable attached to the mounts.  You can cut off
> extra cable but 17 feet is enough to get from the roof of
> the vehicle through the interior and then to the radio.
> > 
> > The few "hamfests" that are in this part of
> the country don't usually end up with RG58/U being
> thrown in the dumpster.  I don't know about your part of
> the country, but not in this part of Texas.  Besides, since
> I do have to purchase RG58/U for use in the cable kits when
> I do need a short piece I just cut it from the spool.
> > 
> > I do use RG58/U for connections (jumpers) from various
> antenna switches to receivers and usually for connections
> from transmitters that are in the 100 watt output or less
> class on frequencies below 30 MHz.  However, I do not use
> RG58/U for any longer runs nor for equipment operating above
> 30 MHz or for transmitters running more than around 100
> watts output.  In fact, all of my antennas (1.8 MHz through
> 432 MHz) except for my 40 meter phased verticals have either
> 1/2 inch or 7/8ths inch Heliax.  I know that 1/2 inch Heliax
> is an "overkill" for such low frequencies but I
> have obtained a pretty large number of 100 foot runs of 1/2
> inch Heliax at no cost over the years and to use anything
> less expensive would require a cash outlay.  I do use
> RG213/U on the 40 meter verticals because of the lengths
> required make coiling up of one leg necessary and Heliax is
> not easy to coil.  100 feet just happens to be the correct
> length to make it from the top of my main
> > tower to about 3 feet inside the ceiling in my main
> radio shack.  From there (the last 4 feet) the jumpers are
> RG213/U to my antenna switches.
> > 
> > Right now there are 8 runs of 1/2 inch and 1 run of
> 7/8ths inch Heliax up my main tower and 4 runs of 1/2 inch
> Heliax up my "short" tower. There are some photos
> of my antennas at
> > 
> > http://k9sth.com/uploads/newantenna.JPG
> > 
> > However, the 27 element 432 MHz yagi is not in those
> photos.
> > 
> > Glen, K9STH
> > 
> > Website:  http://k9sth.com
> > 
> > 
> > --- On Thu, 2/12/09, Carl <km1h at jeremy.mv.com>
> wrote:
> > 
> > I never assumed anyone had to BUY RG-58. That stuff
> winds up in the dumpster at hamfests ever sine RG-8X came
> along. Plus the older the better for loss.
> > 
> > Now thats a real no brainer.
> > 
> > 
> >


      


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