[NLRS] Wait a sec - 1296 Rhombic

Wed, 12 Jun 2002 21:22:28 -0500

Hello to those interested
See the current issue of " ATV Quarterly". MY 440 Mhz Dual Rhombiod  is  on  the
cover of the magizine and the  article with the construction details with
pictures and
some of my experiences with this Great Antenna

J Craswell wrote:

> Hi Jerry Bob and others:
>
> Well I haven't built one so take this with a big grain of salt.  BTW have
> you?  I'm done a little research and follows are some of the particulars.
> #1 the measured results at the Central States.  In my opinion 17 dBi+ is
> nothing to sniff at.  If your putting up an antenna for gain (That is the
> goal, right?) what beats this for the same amount of scratch?  I think a lot
> of us would like to hear about a design with lots more gain (as you say)   I
> don't know about the issue of "noise" in reference to the termination
> resistors.  Perhapes you have a comment and I don't understand that problem
> if there is one?  There are some other things to consider as Bob and others
> pointed out.  Wind loading and "birds."  I might be off track but I thought
> one of the benifits of the Rhombic was the loosness of it's design?   The
> yagi elements at 1296 are pretty touchy as I recall.
>
> In response to your pattern comments.  Having a better pattern to null out
> signals off the sides etc might be important for 20 meters where your trying
> to avoid signals in a pile up but at 1296?  Me?  I'll bank the 17 dBi gain
> and take the odd pattern and hope to hear an unexpected station or two.  BTW
> I've included some other Quotes and messages from the fellow who designed it
> and his comments about it's performance vrs M2, KLM and Rutlands make it
> sound like a pretty good bet.  Along with that is a "snip" from a fellow who
> uses stacked Rhombics for EME on 432.  To be honest that sort of practical
> display is what sells me.
>
> BTW the fellow who really sold me on the Rhombic (in general) was Ed Addey
> of Desert Voices fame who built one aimed at Kuwait and was heads above the
> Yagi and Log folks at the "big time" stations.  I think the fellows he
> worked with the 5 watt packsets were particularly impressed or perhaps I
> should say astonished.  I know I was.  He (along with Dayton) was fond of
> saying that the only antenna to touch the Rhombic is a parabola.  Maybe I
> might be the victim of propaganda, but I don't think so.
>
> 73 de Jay W0VNE
>
> -------------------------------------------------------------------------
> >Has anyone seen details on the rhombic mentioned above?  He seems to
> >have attained 17dBi with what would appear to be a lot less work than a
> >35 element loop yagi!
> ---------------------
> >I remember watching some white haired ol' weasel who, with a dual rhomboid
> >antenna, kicked butt in the 1296 MHz antenna gain competition at the 1996
> CSVHF
> >Society gathering in Bloomington, Mn. You might take a gander at:
> ------------------------------------
> > Steel Bill, Hi  this is Dayton w0ozi
> > The Dual Rhomboids for UHF  are quite small about 6 wavelengths long and
> built
> > on wood boom, so mounting them on tower or mast puts the  ground many
> > wavelengths. Unlike one thinks of , in the HF or even VHF the dimensions.
> the
> > ground reflection is not is part of the operation.
> > The antenna is very Hi gain on major lobe(  about 5 degrees), it is quite
> broad
> > band and works fine for SSB.  From by experience, it will beat anything
> out
> > there with exception of parabola.
> > Dayton Johnson w0ozi
> -----------------------
> 1296 MHz    Gain dBi
>  W0OZI Dual rhomboid HB 17.3
>  KB0PYO M2 35 el Commerical 16.6
>  W3XO Short backfire HB 14.6
>  WA2VOI Narda 15RH Commerical 13.8
> * WA5VJB 10 el yagi, Reference Antenna HB 13.5
>  W6OAL 11 turn helix HB 12.4 dbic
>  WA5VJB 9 el Moonrabbit HB 12.1
>  DJ9HO Dual quad/reflector Commerical 11.3
>  DJ9HO Dual feed loop/refelector Commerical 10.7
>  N8KWX Dual coffee can HB 9.7
>  W0UC Create LP Commerical 9.1
>  K9FYV 6 el End-fire HB 8.0
>  W6OAL Yagi 6 el w/VJB feed HB 7.5
>  N8EHA Conical Sprial Commerical 4.7
>  K9FYV Conical Sprial Commerical 2.5
>  K9FYV Log periodic Commerical .5
> --------------------------------------
> Hi Bernie:
> I've been trying to send you a reply, but don't know how to use my computor.
> I'll try again with my 12/3 message.
> That QST pix has stirred up phone calls, mail and the vhf reflector internet
> activity.
>
> My rhomboids have used 800 ohm terminations. Some of the reflector comments
> on their generating noise I have seen and while probably valid. I'd build
> one and try it. The gain has proven more important from my experience.
>
> I built my first one for 70cm FSATVfour years ago. The original inspiration
> was prompted by an artical in 73 magizine, July 77, Pg24. It worked so well,
> outperforming th M2, KLM, aand Rutlands other use around here for ATV.
>
> I have since rescaled my design for 910 and 1265 and could mail the info if
> you forward a mailing adsress. The 1265 version is what we tested at CSVHF
> antenna measurements range and is pictured in QST.
>
> Hope this reachs you and is of help.
>
> 73's W0OZI Dayton Johnson ------ Submissions: [email protected]
> Subscription/removal requests: [email protected] Human list
> administrator: [email protected]
> --------------------------------------------------------------------------
> 432 MHz Rhombic Antenna Design Jack Albright K0WOW - June 1977
> Last fall Jack, K0WOW copied our EME signals with a 4 dB converter using two
> stacked rhombics. The dimensions of these rhombics are shown in the
> following figure. The design is based on work done by VK3ATN (World above 50
> MHz., QST. Jan. 1968) and K0MQS on 2 meters. The rhombics were stacked
> approximately 2 wavelengths apart and composed of #18 copper clad wire. A
> universal stub was used for matching. K0MQS has tried stacking up to 8
> rhombics and says that a 0.9 wavelength is about optimum.
>
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