Space Hints from the Dominican Republic in 1994

Check out the article in the link below.  I too got a QSL from RS-10! 

https://www.gadgeteer.us/SPAHINT.HTM

The 2 meter portion of the Ray-Gun appears below.  I still have the elements. 

Attempting 2 meter contact, Dominican Republic to Puerto Rico

It is about 100 miles across the Mona Channel.  That is a longshot on 2 meters, but I got the idea when, this past summer, I regularly heard WIDI 99.5 FM in the Dominican Republic from western Puerto Rico.  So over the fall I gathered 2 meter gear, and got a directional antenna and sent all of this gear to the DR.  

Here is the antenna.  Seven elements. I got it through Amazon.  It came kind of incomplete and without any written or on-line instructions.  AI told me to do exactly the WRONG thing with what they assumed was a reflector.  Fortunately I ran into this YouTube video and learned that it was in fact a "ZL Special" antenna, and that it has, in fact, TWO driven elements.  It was through that video that I learned how to assemble this thing.  

My "station" consists of a Heathkit HM-2109.  It is a VHF wattmeter/SWR meter that I bought by mistake.  But I kept it, and it proved very useful in this 2 meter Mona Channel project.  There is a Baofeng UV-5R (boo! hiss!) and a Yaesu FT-470 that KD4EBM gave me.  I have a Communication Concepts 2 meter amplifier -- I must have picked this up at a hamfest.  It promises 35 watts with 5 watts of drive.  The old CCI amp gives the rig good juju. 

This morning I wrote to the hams of western Puerto Rico: 

--------------------------------------------------------

Saludos desde el otro lado del canal de la Mona! 

Soy radio aficionado:  Hi7/N2CQR.   Vivimos en República Dominicana en Cap Cana seis meses cada año.

He notado que puedo escuchar WIDI 99.5 FM aquí.  Parece que hay Tropospheric ducting. 

Como radioaficionado, me gustaría averiguar si podemos hacer contacto en 2 metros usando la misma propagación. 

Tengo: 

Dos transceptores de FM

Un amplificador a 35 vatios. \

Un antenna directional de 7 elementos con un gain de 11.5 db. 

Estoy a una elevación de 7 Pisos.  Puedo ver el canal de Mona. 

Hay alguien en la costa oeste de PR (tal vez cerca de Mayagüez) quien puede hacer un schedule para probarlo? 

O hay un repetidor en la zona que puede usar para averiguar si puedo -- por lo menos -- "kerchunk"  el repetidor?  

Gracias por su ayuda! 

73  Bill  Hi7/N2CQR

-----------------------------------------

Greetings from the other side of the Mona channel!

I am a radio amateur: Hi7/N2CQR.   We live in the Dominican Republic in Cap Cana six months every year.

I've noticed that I can listen to WIDI 99.5 FM here.  There seems to be Tropospheric ducting.

 As a radio amateur, I would like to find out if we can make contact in 2 meters using the same propagation.

 I have:

Two FM transceivers

An amplifier at 35 watts. \

A 7-element directional antenna with a gain of 11.5 db.

I am at an elevation of 7 Stories.  I can see the Mona's channel.

 Is there someone on the west coast of PR (maybe near Mayagüez) who can make a schedule to try it out?

 Or is there a repeater in the area that you can use to find out if I can -- at least -- "kerchunk" the repeater?

 Thank you for your help!

 73  Bill  Hi7/N2CQR

-------------------------------

Stay tuned! 

WD-40, a Hard Drive, a Coat-Hanger Antenna, Dumpster Diving, and Amateur Radio Satellites from the Azores

 

Last month I was talking to Ira VP2EIH on my new 1712 SSB rig.  Ira is interested in satellites.  Talking to him caused me to dig up some old material about satellite operations.   Here is a 2003 QST article about working the satellites from the Azores: 

http://www.gadgeteer.us/AZORESSP.HTM

Regarding the usefulness of WD-40, during my time in the Azores John EI7BA once told me that WD-40 is, "the Pope's pee!"  Apparently that is high praise in Ireland.  It is indeed good stuff. 

Messias CU2BJ is a Silent Key.  I hope Ray CU3GC, WL7CDK is doing well.  

Jack NG2E's Winter SOTA Marathon in the Shenandoah

  

Our friend Jack NG2E is a homebrewer.  He is also a Summits-On-The-Air guy. He does much of his SOTA operations along Skyline Drive in the Shenandoah National Park. Jack's Story Map method of documenting this SOTA trip is very cool. 

Elisa and I are frequent visitors to this amazing park.   Both my kids went to college in the Shenandoah valley, and the park starts just one hour by car west of us.  It is a beautiful place. The Appalachian Trail runs through the park;  we have crossed paths with "through hikers" who are walking from Maine to Georgia. We have also met up with more than one Black Bear in the park (see below).  My son Billy and I launched our Green Hornet rocket from a farm in the Shenandoah valley: https://soldersmoke.blogspot.com/2017/05/still-photos-and-slow-motion-video-from.html

I really like Jack's use of both HF and 2 meter FM.  This makes me think that I should blow the dust off my Baofeng HT and bring it out to the Shenandoah next time we visit.  Jack's 20 meter CW contact with Christian F4WBN in the Pyrenees added a nice element of transatlantic mountain symmetry.  

Check out Jack's Shenandoah Story Map: 

https://storymaps.arcgis.com/stories/c9ff4a13eca24b37bc9dcda0d2dce989

Here's another story map from a SOTA trip into the Adirondacks with info on his gear: 

https://storymaps.arcgis.com/stories/594ca069a27147c1a8d8b79dc1513a72

I know that Jack wants to include a homebrew rig in his SOTA operations.  That would significantly add to the already very high level of operational coolness.  Perhaps Colin M1BUU or Paul VK3HN could provide some suggestions or encouragement in this area. 

Thanks Jack.  Happy trails. Regards to the bears!  

Super-Regeneration is Super-Strange

Farhan VU2ESE is largely responsible for this.  He has recently been talking about VHF.  (More about this in due course.).  This started me thinking about my failed effort in London to get on 2 meter AM.   My plan was to use the transmit portion of this HW-30 (above) with a 2-to-10 downconverter and my trusty Drake 2-B for receive.  

Tony G4WIF also bears some responsibility:  When I expressed interest in Farhan's VHF work, Tony sent me two articles from SPRAT.  Both of them were about super-regenerative receivers.  

Farhan's comments caused me to pull the HW-30 out of storage.  I started poking around the transmitter.  But then I noticed something:  On receive, the AF amplifier was obviously working.  Then, when I tuned through the 2 meter band, the rest of the receiver seemed to be working too.  I fired up the HP-8640B sig gen on 2 meters and turned on the AM modulation.  Indeed, the old receiver was inhaling!  

This launched me into an effort to understand how super-regenerative receivers work.  There are a lot of really weak explanations out there. You get the distinct impression that the person explaining the circuit does not understand it himself.  This makes explaining it very difficult.  I am not the only one to notice this phenomenon:  Mike WU2D commented on this in one of his excellent super-regen videos.  This one:  

https://www.youtube.com/watch?v=QOhNPLT8R10

Mike very kindly said the operation of this circuit seems like "magic."  I was thinking more in terms of Voodoo.  

Howard Armstrong discovered super-regeneration years after he invented plain old regeneration.  The new discovery came around 1921.

It looks like VHF guru Frank Jones had very early misgivings about super-regeneration.  In his 1934 classic 5 Meter Radio Telephony, Jones seems unenthusiastic about the circuit and about our ability to understand it:  "To explain, simply, exactly how this form of detection takes place is not a simple matter, but some of its characteristics are easy to visualize."  In this book, Jones goes on to predict that super-regens will be superseded (!) by superhets.  Indeed, in his 1961 book VHF for the Radio Amateur there are no super-regen circuits; all the receive systems are down-converters to HF receivers. 

Still, with that HW-30 hissing away right next to me, I feel I need to understand how the super-regen works.  I'm not there yet, but I'm trying.  Here are some good resources: 

A good article from Wireless World 1946:  

http://www.r-type.org/articles/art-285.htm  

A student's write up of his effort to understand: 

https://folio.brighton.ac.uk/artefact/file/download.php?file=597679&view=111191

But the best so far (for me) is from Frederick Terman (one of the founders of Silicon Valley) in  his 1943 classic Radio Engineer's Handbook.  Click on the images for a clearer view. 

I will definitely try to get the HW-30's 5 watt AM transmitter going.  I am not so sure I'll do anything with the receiver.  I think this is a matter of picking your battles and "finding joy."   I didn't find joy in FT-8, so I stopped working with it.  Same with my HA-600A, DX-40 Novice rig.  Same with CW in general.  And the same with SDR.  I suspect that super-regen receivers may also fall into this category.  I mean, let's face it, if you are not fond of ordinary regens, is there any real chance that you will like SUPER-regens?  Even Frank Jones seems to have disliked them.  And there is a reason Howard Armstrong moved on to superhets -- they are better! But still, that receiver is hissing away at me...  Stay tuned. 

2 Meter Homebrew: The Fredbox (Video)

I predict a rebirth of interest in 2 meter homebrew.  This will probably hit around Christmas time.  The impetus will come out of Hyderabad, India.  At this point, I can say no more. 

I was thinking about all of this today.  I remembered "The Fredbox."  G3XBM's report on this fantastic rig was carried on this blog before it was even a blog.  And the Fredbox goes back much further in time -- back to the mid-1970s.  It must have been great fun to have QSOs with this rig in Cambridge England back in the day.  G3XBM actually crossed the English channel with this 10 mW rig.  FB.  

When I was in London (2003-2007), G3XBM's post on the Fredbox got me interested in 2 Meter AM.  I had a down-converter that let me listen, and I went as far as modifying a Benton Harbor Lunchbox for the proper AM transmit frequency.  I don't think I made any contacts, but I still have the bits and bobs of this rig, so if anyone in the Northern Virginia area wants to get on,  please let me know -- I will blow the dust off this project and will build a 2 meter antenna.  

Here are more details from G3XBM on The Fredbox:  

https://sites.google.com/site/g3xbmqrp3/vuhf/fredbox 

Hans G0UPL got into the Fredbox in 2009 and 2016: 

http://www.hanssummers.com/fredbox.html