FILES

[Ray Cannon]

This is a place to attach files to be shared with other members.   Identify what the content is in the file name.

[Ray Cannon]

This is a test.  Here is WA5VJB Cheap Yagi Article

[kd7uo.dale]

10GHz Amp Conversion Using HughesNet Satellite System

Just to try this out, here is an interesting article describing how to convert a HughesNet (internet via satellite) module into a 1w 10GHz amp.  I've come across two of these HughesNet units.  Apparently, Hughes upgrades their systems from time to time.  The guy came out to my neighbor's house, put up a new satellite transceiver, and left the old one to be thrown away by the homeowner.  He threw it my way.  I haven't made the conversion yet but plan to do so this summer.  If anyone else has done this conversion and would like to share his experience, I'd be happy to hear about it. 

Dale KD7UO

[Ray Cannon]

Here are some snapshots of the TCK board I built.  I know there are revisions to the instructions 2009, March 2018, June 2018 but I believe the board is the same just the instructions have been updated,

[Ray Cannon]

Here is the output of my W1GHZ transverter.  There are no external amplifiers or isolators or filters. 

An ADF4350 going into the W1GHZ x9 board going into the W1GHZ 10 GHZ transverter.  The IF is an ICOM 817 going through a Downeastmicrowave TCK interface board.

[Ray Cannon]

I should explain.  The five outputs are the LO - IF, LO, LO + IF, LO + 2*IF and LO + 3*IF (the second and third harmonics of the IF are generated inside of the mixer).

Note the levels:

LO-IF        (10080)   -14 dBm

LO            (10224)   -15 dBm

LO+IF       (10368)      5 dBm

LO+2*IF    (10512)   -22 dBm

LO+3*IF    (10656)   -29 dBm

This means the LO rejection from the pipecaps is about 20 dB.

[kd7uo.dale]

The attached marked-up schematics show the changes to the 902 and 1296 schematics to match the parts list I published in July/Aug.  Some of the parts per Paul Wade's original schematics are not easily available.  These changes show how to use the more easily obtained parts.

[Nick Krachmalnick]

Thanks Dale,

That helps. the 33 nh inductor is not the easiest thing to find. I have some on order now.

73's

Nick

N0CYT

CN87uv

On Tue, Sep 4, 2018 at 11:24 AM, kd7uo.dale <kd7uo...@gmail.com> wrote:

The attached marked-up schematics show the changes to the 902 and 1296 schematics to match the parts list I published in July/Aug.  Some of the parts per Paul Wade's original schematics are not easily available.  These changes show how to use the more easily obtained parts.

--
You received this message because you are subscribed to the Google Groups "PNW Microwave" group.
To unsubscribe from this group and stop receiving emails from it, send an email to PNW-Microwave+unsubscribe@googlegroups.com.
To post to this group, send email to PNW-Mi...@googlegroups.com.
Visit this group at https://groups.google.com/group/PNW-Microwave.
To view this discussion on the web visit https://groups.google.com/d/msgid/PNW-Microwave/7b56e9ba-b8bd-41c5-aa20-775610bc946f%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

--

Nick
nick...@gmail.com

[Ray Cannon]

Another picture - notice how 50ohm load and 8 volt regulator are both used to mount board while using the case as a heat sink.

[Ray Cannon]

The 8 volt regulator is somewhat hidden by the electrolytic capacitors.

[Ray Cannon]

FWIW:  Here is an analysis that was done by W7PUA and W7CQ on the WA5VJB cheap antenna.  With the original feed the SWR is poorly behaved.  The problem was tracked down to the feed.  The behavior can be greatly improved by a slight modification of the feed using a quarter-wave of UT141 to make a T match balanced feed.  People have successfully used the original design but you might find the pattern is lopsided as well as find the SWR unpredictable.  I have scraps of UT141 for anyone who wants to try the balanced feed.

Here are W7CQ's observations:

Look at the transmitted VSWR on the original Feed of the WA5VJB 1296 antenna:  These results were all over the place and all depended on the placement of the feed line. You could get almost any swr you wanted by moving the coax around.  The feed was coupled to the antenna all over the place.  Results could not be reproduced accurately  This was noted by Rick (KK7B) when this antenna was tested on the outdoor range.

Using the Modified feed in the picture at the top of the page - moving a the feed line had almost NO effect on the results.  The antenna gain went from somewhere in the 7 to 8 db range on the original feed to  about 13 dB  and the antenna performs properly now.

The results of the balanced feed solved the problems experienced on the outdoor range on October 24 2015.  The VSWR curves show a very good antenna with a shallow drop off below 1296 and a sharper drop off above 1296.  LOOKS GOOD.  AND IT WORKS!   Nice cheap antenna!

[VE7HR]

And check out Rick, KK7B’s presentation from a couple years ago conference that give some more details and some examples of both 902 and 1296.  It is a very well thought and informative presentation.  

Dave

VE7HR 

Sent from my iPhone

--
You received this message because you are subscribed to the Google Groups "PNW Microwave" group.

To unsubscribe from this group and stop receiving emails from it, send an email to PNW-Microwav...@googlegroups.com.

To post to this group, send email to PNW-Mi...@googlegroups.com.
Visit this group at https://groups.google.com/group/PNW-Microwave.

To view this discussion on the web visit https://groups.google.com/d/msgid/PNW-Microwave/1468d3fe-66a4-4e66-afa4-7125b04660e3%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

<WA5VJB_Cheap_Antenna_Original.JPG>

<WA5VJB_Cheap_Antenna_New_Feed.JPG>

<WA5VJB_Balanced_Feed.jpg>

<balun.jpg>

[Rod Johnson]

Yes, the cheap yagi design can definitely be improved upon.

   The original design was to get stations operational on the band with virtually no antenna expense.  That lightweight and robust design has worked very well for many people for roving and basic station use.  As Kent Britain mentions in the very beginning of his article, if you are looking to build an EME station, you should look elsewhere.  I think that applies to serious terrestrial work also.

    I seldom have actual bearings available when using my 'cheap yagi' antennas, and I usually have a directional 2M or 432 beam in use at the same time, which helps me get 'in the ballpark'; for pointing.  I usually find the two beam headings do not agree, but with the simple unbalance feed on the 'cheap yagi', I m not surprised, nor deterred from it's use.

  I would suggest that one should build the very quick and dirty version,( or even just the folded driven element-remember that element design was for a nominal 50 ohm feed as the basis for the whole antenna design) , for testing and occasional local/portable use.  Get used to using the transverter and it's operation. make more contacts than expected and then either revise the one you have, build another of the revised design, or build/buy something that is a much more professional rendering, and that you will be concerned about bending or breaking.  ( BTDT!)

  More serious work, such as for long term installations and/or long range contact attempts, certainly justify modification of the original design, or purchase/construction of a much more sophisticated design antenna.

 Rod Johnson

. 

[Mark Spencer]

Another option for those of us who are not into building antennas is one the LPDA style cellular beam antennas.   I've used mine with success on 927, 1296 and 2.4 GHz (wifi.)

Mark Spencer

VE7AFZ

nets...@gmail.com

To view this discussion on the web visit https://groups.google.com/d/msgid/PNW-Microwave/16655efd181-1ec4-8d87%40webjas-vaa087.srv.aolmail.net.

[John Petrich]

Thank you Ray for all of your trouble.  Good information to file away and study.  Yes, the particular feed of these yagi’s brings “problems”.  And, as you mentioned, the proper ‘fix’ is to decouple the feedline from the antenna.  A revised balanced feed and a balun is likely the best approach .  However, the feedline in the original design can be decoupled with ferrite cores as well.  Just say’n.

 

I’ve built and tuned the WA5VJB wood boom yagi’s for 144 through 1296 MHz.  In each case, decoupling the feedline was easily accomplished by running the feedline from the feed point down the centerline of the boom, back to the reflector element,  and adding suitable ferrite cores at the feedline/feed point junction.  The SWR readings are easily adjusted.  No amount of moving the feedline or running my hands along the feedline has any impact on the SWR.  That said, if I wanted to rebuild my antennas, I’d change the feed to the balanced system just as you describe.

 

By way of explanation, the symptoms that Jimmy, W7CQ, described are the result of common mode currents on the antenna feedline.  The common mode currents are on the outside of the coax shield, the result of unwanted coupling of the feedline to the antenna proper.  A feedline with the common mode currents becomes part of the antenna.  The feedline radiates as the antenna radiates.  Some of this feedline radiation couples directly back to the antenna and distorts the pattern left right and center.  Some of the radiation on the feedline, away from the immediate proximity of the antenna, radiates both horizontal and vertical radiation.  Lord knows where.  This situation results in a distorted radiation pattern with undesired side and back lobes, noise pickup on receive, and on and on.  The SWR will jump around as you run your hand up and down the feedline.  “The feedline tunes the antenna” it used to be said.  The cause of common mode currents is the unbalanced feed that you pointed to and the solution is decoupling the outside of the coax feedline from the antenna.

 

Regards,

John, W7FU

 

From: pnw-mi...@googlegroups.com <pnw-mi...@googlegroups.com> On Behalf Of Ray Cannon
Sent: Monday, October 8, 2018 3:38 PM
To: PNW Microwave <PNW-Mi...@googlegroups.com>
Subject: [PNW Microwave] Re: FILES

 

FWIW:  Here is an analysis that was done by W7PUA and W7CQ on the WA5VJB cheap antenna.  With the original feed the SWR is poorly behaved.  The problem was tracked down to the feed.  The behavior can be greatly improved by a slight modification of the feed using a quarter-wave of UT141 to make a T match balanced feed.  People have successfully used the original design but you might find the pattern is lopsided as well as find the SWR unpredictable.  I have scraps of UT141 for anyone who wants to try the balanced feed.

--