atn summer 2019 newsletter - rollinvideo.com€¦ · atco news activities ... from my work-bench...

ATN Summer 2019 NewsletterP.O. Box 1594, Crestline, CA 92325

In this issue

PG-1.........New ATN Chapters.

PG-2.........ATN-MO’s first meeting

PG-3.........ATN-DE & Future of Digital ATV

PG-4.........ATN-FL ATV Activity

PG-4-7......ATV at Hamvention 2019

PG-8.........ATCO News

PG-9.........ATN-AZ Summer BBQ Announcement

PG-10.......ATN-CA Summer BBQ Announcement

PG-11-12..Doherty Amplifier, what are they?

PG-13.......ATN-AZ News

PG-14.......ATN-CA & NV News

New ATN Chapters/Groups

We have a new state chapter formed in Delaware.Dave Stepnowski KC3AM is president and VinceVitullo N3BFZ is VP. Our new chapter has two re-peaters, KC3AM at Ebright 423.0 MHz DVB-T 2MHz B/W output and 421.25 MHz VSB output atDarby. Both repeaters have a 439.25 MHz LVSB(AM) input and are linked.

We have a new state chapter formed in MissouriMel Whitten K0PFX is president and Earle YoungWD0FCH is trustee. Their St Louis area repeateris located in Maryland Heights and is all digital.Input is 440 MHz DVB-T 4 MHz B/W and output is426 MHz 4 MHz B/W with full HDTV capability.

Interested in forming your own ATN chapter buthave some questions?

ATN chapters each are self governing with theirown officers. As a group we are a voice to promotethe ATV mode in our ham radio hobby and we fightto protect our mode when outside groups proposeto take our spectrum or request experiment li-censes to operate overlaid on our ATV spectrum.

Each chapter contributes technology and at timesequipment with all chapters benefiting from ourtotal group expertise.

Not an ATN member but would like to continue toreceive our newsletter, please contact Roland Hoff-man KC6JPG at [email protected] to sign up.

ATN Summer 2019 Newsletter

June 24, 2019, Mel Whitten K0PFX asked mem-bers of our ATV group if they would like to get to-gether for dinner to finalize our discussions aboutforming an ATV club that had both local control butalso be part of a larger ATV community while ourguest Mike Collis WA6SVT was in the area onbusiness. We have seen the great things ATN withits many chapters have done and we decided toformalize our group into the ATN family.

Our group put a full digital in-band ATV repeater to-gether a couple of years ago, call is WB0FCH. Weuse the following perimeters:

Input: 440.0 MHz at 4 MHz B/WOutput: 426.0 MHz at 4 MHz B/WFormat: DVB-T at 16 QAM, h.264Antenna: Omni vertical polarityTower: 85 feet + 15 ft mastT.P.O.: 10 wattsLocation: Maryland Heights (west St. Louis)

We have the repeater at our trustee Earle YoungWD0FCH’s QTH. Our repeater supports HDTV orSD. We have no plans for analog ATV at this time.Currently we are using a separate RX antenna atthe top of the mast and a TX antenna at about 75ft side mounted.

We plan to do some major upgrades to the an-tenna system and tower. The goal is to get reliableservice to two members who are having issuesseeing and accessing the repeater. We plan to add20 feet to the tower, upgrade to a single NewtronicsSpirit series 9 dBd antenna and add a duplexer.Mel has been in contact with Jim Andrews fromKH6HTV video and DCI filter for specifications.Mike WA6SVT donated a 35 watt amplifier for the

repeater.

Mike WA6SVT fixing a jumper cable on TX Ant.

73, Mel K0PFX

Left to right:

Rich KnodeKB0CCL

Armand Hoff-stetter KD0PXF

Mel WhittenK0PFX

Mike CollisWA6SVT

John Adels-berger W0NZG

Earle YoungWD0FCH

Ron Ochu KO0Ztaking thephoto.


ATN-Missouri’s First Meeting

Our ATV group in Delaware and Philadelphia areahave been running digital ATV over the last yearand a half. Last month the local coordinatingcounsel T-MARK has put out a draft band plan withcomment period ending on the 9th of July. In the70 cm band, the draft mentions in the repeater ATVfrequency section “Analog TV Only” and“No DigitalTV”. In the body of the draft it says “Digital TV useon 440 has been Prohibited” They are proposingto allow analog and digital simplex/remote baseand hot spots among other uses to overlay our ATVchannel in the 438-440 MHz segment. We sent outa notice via the Digital ATV Forum and contactedsome of the well connected ATVers for help. Wehave been affiliated with ATN for years anddecided to make this affiliation a bit more formal,we are now ATN-DE. We received help with ourresponse to T-MARK from other ATN chapters.

Our group has two repeaters that are linked. Thelocations are Ebright and Darby, they are about 18miles apart with Darby being closer to Philadelphia.

Our repeater perimeters:Input (both): 439.25 MHz LVSBOutput Ebright: 423 MHz DVB-T 2 MHz B/WOutput Darby: 421.25 MHz VSBAntennas: Omni Horizontal Polarity

We link from Ebright to Darby on 1252.0 MHz FMand from Darby to Ebright on 2420 MHz FM.

73, Dave KC3AM

Page-3 ATN Summer 2019 Newsletter

ATN-Delaware & Future of Digital ATV


ATN-FL ATV ActivityWolfgang Snitsar KV4ATV setup a portable ATVstation at the 2019 “Blessing of the Fleet” at the St.Andrews Marina April 20, 2019. This allowed theevent officials to see the crowds for public safety.Part of the event was seen by some of the com-munity on shore and on yachts by tuning ontocable channel 59 with their TV sets hooked up toan antenna.

Wolfgang used his MFJ 5 watt ATV transmitter on434.0 MHz with a J-pole antenna above the cam-era tripod to transmit the event.

Later in the day, Miss Florida, Nicholette Jenningsstopped by to pose for a photo and see what ATVis all about.

Wolfgang and his son Vlad are coming to the ATN-CA BBQ and to pick up a used Chevy Suburbanand bring back antennas and other equipment forthe repeater under construction. On his way back,he will have ATV on 434/439 MHz, IP video stream-ing and APRS so stations can see when he andVlad will be nearing town for their cross countryATV trek on their way back home in Florida.73, Wolfgang KV4ATV

ATV at Dayton Hamvention 2019Dayton Hamvention®, hosting the 2019 ARRL Na-tional Convention, chalked up its third year at itsnew venue, the Greene County Fairgrounds andExpo Center in Xenia, Ohio. Amateur Radio'slargest annual gathering took place May 17 - 19.Hamvention officials have not yet released a 2019attendance figure, but last year's show drew28,417 -- the third largest attendance ever. Formany hams, Hamvention offers an opportunityeach spring to renew old acquaintances and makenew ones, and for manufacturers to debut their lat-est and greatest gear.

There were numerous people wandering around theHamvention that deserve a second look but beloware a few of the notable ones I found as I was sittingin the ATN booth observing the passersby. Note thatwe are still in a portable tent set up for the Hamven-tion to accommodate the extra vendors and groupswanting a table and space to sell their “stuff”. The“tent” really isn’t that bad. It was supposed to be re-placed with a permanent structure but it hasn’t hap-pened yet and maybe never will. Oh, well…...WA8RMC

ATN Booth and ActivityDave Stepnowski KC3AM from our Delawarechapter obtain the booth again this year. DavePelaez AH2AR from our DARA chapter set up thebooth for full DVB-T transmit and receive via theW8BI ATV repeater from Huber Heights 19 milesaway. Thank you to both Dave and Dave for mak-ing the ATN booth a success this year!

Norm Hill WD6OMV at the booth.423 MHz and 1280 MHz Yagi and Loop Yagi.

We had good pictures most of the time from Dave’ssetup. The Yagi antennas were about 15 to 18 feetabove the ground. We could access the repeaterwith as little as 2 watts. Not bad for a 19 mile pathon 23 cm band. We had several inquiries aboutATV and many were surprised that ATV now hasdigital modes.

Mike Collis WA6SVT answering questions

Art Towslee WA8RMC manning the ATV station.

Art and Mike looking for that great deal in the flea market.

...WA6SVT ATN Summer 2019 Newsletter

Friday Night ATV DinnerThis year’s ATV dinner was a huge success! Wehad over 35 people in attendance which, I believe,is a record. For those of you that missed it or justchose to not attend, you missed out on good ATVdiscussions. Dinner started about 6:30 PM.

Ron Cohen K3ZKO describes ATV activity in his area

Gary Heston W6KVC transmitting live IP video toATN-CA & NV Repeaters.

We had a round table discussion from the partici-pants about happenings around the country and Canada. Our great dinner was hosted by the ChinaGarden Buffet restaurant. Of particular note but notpictured, we found that a person traveling the far-

thest from theDayton areawas from Fair-banks, Alaska.Dinner wrappedup about 9:30PM.

Come join usnext year!

...WA8RMC

Bill Brown WB8ELK discusses his balloon launchadventures

ATV Dinner Group Photo, Three photos spliced to make a panoramic picture

Enjoying dinner in our private dining room


Hamvention ATV FORUM

I was pleasantly surprised about the large turnoutfor the ATV forum this year. A rough count showedthat over 100 attended. In addition, interest in digitalATV was intense. That’s a good sign for I have seenlow interest in the recent past.

This year we were well represented with speakerssupplying DATV information.

We started with a short introduction and then intro-duced Gordon West, WB6NOA. Gordo always hasa knack of being able to “wake up the crowd”, so tospeak, so the following material won’t be met withsnoring.

He did a warm up with fun audio sounds and oneliners.

Next Mel Whitten, K0PFX, talked about Exploringthe world on High Definition Television. Mel ex-plored the current digital ATV gear available andhow it can be used to assemble a high-perfor-mance station.

Next Mike Collis, WA6SVT, described the new dig-ital features of ATN’s repeaters in the southwest.

Last, I gave a wrap up and talked about the DATVMiniTiouner DVB-S/S2 receiver module.

...WA8RMC ATN Summer 2019 Newsletter

ATCO NewsACTIVITIES ... from my Work-benchWelcome to the summer sea-son, guys (and gals). Rightnow, I’m just sitting here think-ing about all of the things I’mNOT going to do today. Lucky

for me I just got a reprieve because although thegrass needs cutting, I just heard thunder outside.How about that! Now I have a valid excuse. On tothe Ham stuff…

I’m busy working on my MiniTiouner-Express re-ceiver assemblies and DATV-Express transmitterboards for sale. That work is going to start windingdown a little soon so I can pay some attention toother Ham things. However, we are now talkingabout possibly creating another DATV relatedproduct so the lull in the action may be short lived.Therefore, I need to finish a few MiniTiouner as-semblies and get them in the mail to the UK for dis-tribution first.

Next, I noticed the repeater 439MHz input is not assensitive as it once was. It has been many yearssince I last checked on the components so I de-cided to remove the filters, signal splitter and ana-log receiver for a checkup at home. Re-tuninginterdigital filters at the repeater site is a huge painso the work is better done off site.

There are two 7 pole interdigital filters in this lineand it is tricky aligning them. I was anticipatingeliminating one of them to see if we could get bywith just one filter. Bad idea! The co-channel RFnoise there is the worst anyone will encounter so Ifound the extra 1.2dB loss using 2 filters is a verysmall price to pay. The extra filter steepened theskirts a lot which kept the 439MHz bandpass awayfrom our 449.975MHz link frequency and our427.25MHz main transmit frequency.

Also, there are FM repeaters in the vicinity startingat 443MHz so there is a lot to contend with. I addeda high IP3 DEM preamp now to cope with the highlevels of interference near 439, establish a goodnoise figure and make up for the 3.5dB signal split-ter and 2.4dB filter loss. So far, so good. Thingshave improved dramatically. Now a 200mw signal

from me 14 miles away produces a P3 signal intothe repeater. Not bad so far.

However, now I found another unsolved problem. Ifind that the 200mw 439 signal is OK during theday but at approximately 7 to 8PM each day some-thing blocks the incoming signal such that it takesover 10 watts to barely overcome it. Strange. Thenext morning it is OK again and throughout the daybut about 7:30PM it gets blocked by some un-known source.

I need to make a trip there with my Spectrum Ana-lyzer but due to ongoing building repair work, I’venot been able to go there after hours. I have a cluethough that I’m hoping will be the issue. Therooftop building beacon light contains an LED bulblocated about 5 feet away from the 439 receive an-tenna. LED lamps have been known to produce RFinterference and since the interference starts aboutdusk and goes away at dawn, just maybe I’ve lo-cated it. I’ll see soon. If that’s true, it is probablycausing interference to some of the commercial ra-dios there too. If that’s the case, I’ll bet it gets fixedREAL FAST. We’ll see.

I’ve done no more investigation into the possibilityof locating a link to Dayton at Jones road in SouthVienna. Dave Pelaez, AH2AR, determined it ISpossible but that was before the trees grew leavesin the Spring. We decided to re-test sometime afterthe Dayton (Xenia) Hamvention. That needs a re-visit to determine the course of action.

That’s about all for now. More later, Stay tuned!

...73 Art, WA8RMC


��

M

2

��

M

it gets fixed REAL FAST. We’ll see.

2

Our host this year for the Arizona ATN BBQ will beRod Fritz WB9KMO at his East Mesa QTH.

Rod’s address is 8334 E. Culver St., East Mesa.Phone is 480-322-5149 talk in frequency is447.175 MHz, tone is 100 Hz. Doors open at 11AM, lunch at noon and meeting to follow.

We plan to show the group our new ATV link toWhite Tank and Mt. Lemmon and the Mesa ATVand voice repeaters. Rod has a very large openconcept living/dining area that can accommodateup to about 30 and a pool for those who want toswim. If you bring young children, please makesure an adult is with them in the pool area.


ATN-AZ Summer 2019 BBQ & Meeting Announcement Saturday July 13th

Loop 202

E. Mc Kellips Rd.

E. Culver St.

Hawes

Loop 202

East Mesa

WB9KMO’s QTH

Our host this year will be Tom Board WB6HYH &Christine Board at their Rancho Cucamonga QTH.

Their address is 8236 Matterhorn Ct., Rancho Cu-camonga. Phone 909-472-1410 Talk in 1286.15MHz/223.82 MHz tone 85.4 Hz or simplex on146.43 MHz, tone 100 Hz. Doors open 11 AM,BBQ at noon meeting to follow. ATN-CA will pro-vide the meat and guests are encouraged to bringa side dish. Please contact Tom to RSVP and whatside dish or refreshment you plan to bring. (Size toplan for: We usually have about 30 to 35 show up).


ATN-CA Summer 2019 BBQ & Meeting Announcement Saturday August 10th

To I-210

Haven

Ave

E. Foothill Bl.

Hermosa

Ave

Devon St.

Chelsea WayMatterhorn Ct.

8236Hampshire St.

I-15

I-15

I-10

E. Foothill Bl.

Malven

Doherty Amplifiers what are they?BackgroundFor years ATV power amplifiers have been class Afor low level stages used for lease amount of dis-tortion and class AB for low distortion and better ef-ficiency as PAs. In the analog days most ATVstations used off the shelf linear amplifiers thatwere typically used for SSB, CW and FM modesbased on land mobile UHF transistors that weredesigned for class C use but biased to try andmove the transistor into class AB. They were OKfor analog but still had some objectionable distor-tion because their power curve was not linearenough. When Digital ATV came on board, theseamplifiers would not reproduce a digital ATV signalproperly.

Some of the class AB bipolar RF power moduleswould work at greatly backed off power levels, thenewer MOS or LDMOS power modules workedbetter due to the LDMOS FET’s ability to betterhandle the short duration peaks in the RF enve-lope. For broadcast TV service, analog RF poweramplifiers worked well for the transition to DTV.Most of these UHF amplifiers were IOT tubes withsolid state IPA drivers. Solid State transmitters atthe time had poor efficiency and usually limited tolow and medium power.

About ten years ago LDMOS 32 volt transistors be-came the transistor of choice allowing their use inbroadcast amplifiers to obtain 25 % efficiency.Many of the older broadcast UHF RF amplifiermodules and pallets were now surplus, manyATVers have used these for DATV. In the case ofbroadcast TV service, the AC power to RF powerefficiency with solid state with its poor efficiencyand resulting large electric bills, broadcasters stillfavored the use of IOT and tetrode final amplifiers.

About four years ago 50 volt LDMOS push-pullFETs were introduced that improved gain, outputpower and efficiency in the 35 % range. These new50 volt LDMOS devices are used in the newesthigh end power amplifiers made by W6PQL andothers for high power ham radio UHF and VHF am-plifiers. In order to reach or surpass IOT or tetrodeamplifier efficiency a new amplifier was designed.The Doherty amplifier greatly improved efficiencysurpassing the IOT and tetrode amplifier.

How they workFirst, let’s review existing push pull solid state UHFpower amplifier technology. The amplifier stage isusually a push pull, which is a balanced set of FETsor Bipolar transistors with one amplifying the posi-tive half of the of the RF cycle and the other thenegative side. Each transistor is biased for classthe class AB mode so the transistor is turned onenough so no RF envelope transition distortiontakes place.

Push-pull is how most audio amplifier power am-plifiers work and give fair to good efficiency. In thecase of DTV modes there is a high peak to averagelevel difference usually in the 6 to 8 dB range andwhy an amplifier rated for 100 watts in SSB or CWwill only make about 15 to 20 watts average digitalpower. This backed off power gives about 30 per-cent efficiency while at saturation efficiency is near65 percent. The UHF push pull amplifier has agreat amount of symmetry when looking at the am-plifier board as seen below.

Doherty amplifiers on the other hand look asym-metrical. They still employ two transistors, but eachis optimized and biased for different parts of thepower curve. The main or carrier transistor is bi-ased class AB as a single ended amplifier and isused to amplify the lower level or average powerlevel of the DTV signal. The other transistor knownas the peak transistor is biased class C and its biasis set to keep the transistor cut off until the peakpart of the signal starts.

This level is about 6 to 7 db below amplifier satu-ration. This greatly improves efficiency. Dohertyamplifiers only amplify the positive half of the RFwaveform. The resulting negative clipping causesharmonic distortion and a low pass filter is requiredto reduce harmonic distortion and the filter also re-stores the negative half of the waveform.


Push Pull UHF RFPallet


One more enhancement to discuss, the carriertransistor will saturate at about 25 percent of fullpallet saturated power. What is needed is a way topull the carrier transistor into peak amplifier modeonly during the peak part of the signal but remainas class AB during the bottom 25 percent of thepower curve.

The peak transistor when in conduction duringpeak RF drive is used to pull up the carrier transis-tor into peak mode allowing more power to be gen-erated as well as power sharing between the FETs.This is done by placing a quarter wave strip line(transmission line) between the carrier and peaktransistor.

This is due to the quarter wave line inverting theload impedance to a lower level to the carrier tran-sistor (like adding more loading to your HF ampli-fier). This lowering of the impedance allows thecarrier transistor to supply more RF current thus itssaturation level has been raised to match the sat-uration level of the peak transistor.

The quarter wave phase inverter on the output ofthe carrier transistor delays the signal 90 degrees,another 1/4 wave line is needed on the input stageof the peak transistor or a 3 dB (0 and 90 degreeoutputs) hybrid splitter is used so the signal at theT junction is back in phase.

Some Doherty designs use a dual transistor withthe peak side having 1.5 times higher power ratingfor even better efficiency. Note the difference in ef-ficiency between class AB push pull and Doherty

using balanced transistors (symmetrical) and tran-sistors with the peak transistor rated for higherpower (asymmetrical).

It is possible to convert an existing push pull RFpallet that has two push pull stages in parallel intoa narrow bandwidth Doherty amplifier by removingthe output 3 dB hybrid and placing a simple teeconnection in its place. Because the quarter wavelines are now far away from the transistor outputtabs, off frequency use from the quarter wave linesand hybrids will cause faster phase shifting.

Bias modifications: The transistor used for the peakamplifier will need to have its bias adjusted forclass C. This allows you to use an existing palletyou are now using to be converted to a Dohertyhigh efficient amplifier. A harmonic filter would beneed to be added as well.

It should be noted that for most DATV use, classAB push pull amplifiers ran backed off is still theeasier way to go as pre-distortion is not needed forthe lower power levels typically used.

For DATV DXing and a high power repeater output,Doherty amplifiers may be worth looking into. Anexciter with adaptive pre-distortion is recom-mended when using Doherty amplifiers to makebest use of the added efficiency at the higher drivelevels used due to some increased distortion ascompared with class AB push pull amplifiers.

73 Mike WA6SVT

Doherty UHF Amplifier Pallet

Carrier Amp 1/4 impendenceinverter

T-junction & matching

Input Splitter Peak Amp �� !��"��#$%�&'()%�*+�%++,&,%-&.�)%(/'/�0*1%(�+*(�2$%�3/.44%2(,&56�7*$%(2.�&*-+,8'(52,*-�,/�9,++%(%-2�%)%-�+(*4�2$%�:.44%2(,&56�7*$%(2.�&*-+,8'(52,*-�5-9�5/�/$*1-�;%+*(%<��=*2$�7*$%(2.�2.0%/�5(%�45(>%96.�9,++%(%-2�+(*4�2$%�2(59,2,*-56�&65//�3=�5406,+,%(�&'()%<��385,-?�-*2�*-6.�9*%/�2$%�3/.44%2(,&56�7*$%(2.�&*-+,8'(52,*-�$5)%�/';/25-2,566.�,40(*)%9�%++,&,%-&.�2$(*'8$*'2�2$%�&'()%�*)%(�2$%�*2$%(�@�2.0%/?�2$%�&'()%�,/�4'&$�A/2%%0%(B�$5),-8�2$%�%++,&,%-&.�(,/%�C',&>6.�5-9�;%�1,2$,-�*-6.�5�+%1�0%(&%-258%�0*,-2/�*+�45D,4'4�585,-�1,2$�2$%�5406,+,%(�*-6.�52�2$%�EFF�1522�6%)%6<��3;*)%�2$%�EFF�1522�6%)%6�*-6.�5�+%1�4*(%�0%(&%-258%�0*,-2/�5(%�85,-%9�5/�2$%�0*1%(�,/�,-&(%5/%9<�� G�� H�"��I�� !��"�� J-�K,8'(%�@L?�2$%�0*1%(�,-0'2�)%(/'/�5)%(58%�*'20'2�&'()%/�5(%�%//%-2,566.�2$%�/54%�;%21%%-�2$%�/.44%2(,&56�7*$%(2.�5-9�2$%�5/.44%2(,&56�7*$%(2.�5/�1*'69�;%�%D0%&2%9�>-*1,-8�2$52�2$%�5)%(58%�/,9%�*+�2$%�7*$%(2.�5406,+,%(�05,(�,/�'-&$5-8%9<��#$%�0%5>�0*1%(�&'()%?�$*1%)%(?�+*(�2$%�5/.44%2(,&56�7*$%(2.�/$*1/�2$%�/54%�2.0%�*+�8(5&%+'6�85,-�9%8(5952,*-�5/�2$%�/.44%2(,&�7*$%(2.�5406,+,%(�;'2�1,2$�,-&(%5/%9�0%5>�0*1%(�&505;,6,2.� 5-9�585,-�-*2�/$*1,-8�5-.�/,8-/�*+�$5(9�&*40(%//,*-�*(�/52'(52,*-�%)%-�52�2$%�E>M�0%5>�*'20'2�6%)%6<��#$,/?�&*'06%9�1,2$�2$%�,-&(%5/%�,-�%++,&,%-&.?�/$*'69�4%5-�2$,/�05(2�,/�%)%-�4*(%�/',25;6%�+*(�(%0(*9'&,-8�5-�NK7O�2.0%�/,8-56�2$52�$5/�5�$,8$�0%5>�2*�5)%(58%�(52,*�P�&(%/2�+5&2*(�2$5-�2$%�/.44%2(,&56�7*$%(2.�&*-+,8'(52,*-<�M$%-�6**>,-8�52�2$%�/,8-56�0%(+*(45-&%�*+�2$%�5/.44%2(,&56�7*$%(2.�5406,+,%(�5-9�&*405(,-8�,2�2*�2$%�/.44%2(,&56�7*$%(2.�5-9�2(59,2,*-56�&65//�3=�5406,+,%(/?�2$%�-52'(56�/,8-56�0%(+*(45-&%�Q'-&*((%&2%9R?�5/�4%-2,*-%9�;%+*(%?�585,-�500%5(/�2*�;%�0**(�,-�&*405(,/*-�2*�2$%�&65//�3=�5406,+,%(�0%(+*(45-&%<��K,8'(%�@S�;%6*1�/$*1/�2$%�'-&*((%&2%9�/$*'69%(�5-9�OTU�6%)%6/�*+�2$%�&65//�3=?�:.44%2(,&56?�5-9�3/.44%2(,&56�7*$%(2.�5406,+,%(/<��3/�&5-�;%�/%%-�;*2$�2$%�/.44%2(,&56�5-9�2$%�5/.44%2(,&56��7*$%(2.�5406,+,%(V/�-52'(56�'-&*((%&2%9�0%(+*(45-&%�-%)%(�4%%2/�2$%�(%C',(%4%-2�+*(�KWW�/$*'69%(�4,-,4'4�/0%&,+,&52,*-/�5-9�,/�*-6.�5&&%025;6%�+*(�OTU�0%(+*(45-&%�52�2$%�SF�1522�6%)%6�45>,-8�,2�,-+%(,*(�2*�2$%�/.44%2(,&56�7*$%(2.�1$%-�'-&*((%&2%9�5/�2$%�/.44%2(,&56�7*$%(2.��4%%2/�2$%�OTU�/0%&,+,&52,*-�;%6*1�2$%�XF�1522�*'20'2�6%)%6<��#$%�8**9�-%1/�,/�2$52�2$,/�5406,+,%(�,/�56/*�C',2%�A&*((%&25;6%B�1,2$�4*9%(-�9,8,256�6,-%5(,Y52,*-�2%&$-,C'%/<��:$*1-�;%6*1�,-�K,8'(%/�@Z?�@X?�5-9�@[�,/�2$%�0%(+*(45-&%�*+�2$%�/.44%2(,&56�7*$%(2.�5406,+,%(�1$%-�&*((%&2%9<��#$%�*2$%(�8**9�-%1/�,/�2$%�599%9�0%5>�0*1%(�&505;,6,2.�566*1/�,2�2*�;%�&*((%&2%9�4%%2,-8�/,8-56�C'56,2.�/0%&,+,&52,*-/�-*1�52�2$%�@FF�1522�*'20'2�0*1%(�6%)%6�+*(�3#:W�E<F�P�[\]:=<�� ̂��_�� "��Output Power in Watts


ATN-AZ News

Our group is getting ready for our summer BBQ atRod Fritz WB9KMO’s QTH in East Mesa. Rod willbe showing the Mesa ATV repeater and the newlink system under construction to link to both Mt.Lemmon and White Tank.

The old direct link between Mt. Lemmon and WhiteTank was over 124 miles. The point to point linkwas on 2417.5 MHz FM TX at White Tank and RXat Lemmon. The 2417 MHz link provided a goodsignal. Going the other way, White Tank used the8’ dual band dish to pick up the output of Mt. Lem-mon’s main VSB analog transmitter and signalswere in the P3 to P4 range.

After Rod moved to Mesa from California he put upan ATV repeater. He is able to pick up Mt. LemmonATV repeater snow free with a 24 element LoopYagi snow free. He is much closer to Lemmon atabout 80 miles to the southeast. White Tank isabout 51 miles to the west and Rod received itsnow free. Awhile back we added a 5910 MHz FMtransmitter to White Tank to provide a better FMlink to the Mesa repeater as well as an FM outputoption for members to look at directly.

About two months ago we received word that thesite owner was planning on charging added rentfor our 8 ft dish. With that in mind as well as thebetter signals Rod gets at his QTH, we decided topull the old direct long distance link for a link viaRods QTH. The 5712.5 MHz transmitter at Rod’sQTH and receiver at White Tank was already thereto link the Mesa repeater. All we needed to do waspatch in the 1277.25 MHz receiver to pick up Mt.Lemmon and one side of the link would be finishedand this time with a snow free picture.

To complete the link, we add the 2417.5 MHz linkwe took down from White Tank and add a dish to-wards Mt. Lemmon. Connect up a 5910 MHz FMlink receiver at Rods QTH to pick up White tank in-stead of using the existing 1253.25 MHz receiverat Rod’s QTH and connect the 5910 MHz receiverto the 2417.5 MHz transmitter and we are back inbusiness with a full two-way link. As an addedbonus, Mesa ATV repeater will have a direct link to

Mt. Lemmon as well as the existing direct link toWhite Tank. The hardest part will be a tower climbat Mt. Lemmon to rotate the 4 ft. link dish about 20degrees to the east to aim it at Rod’s QTH. The linkdish is 110 ft up the tower as seen below.Mike Collis WA6SVT at 100 ft nearing the link dish

Kevin Jacobson AD7OI (L) & Rod Fritz WB9KMOat White Tank.

ATN-CA News

Our group is getting ready for our BBQ on August10th at Tom WB6HYH’s QTH in Rancho Cuca-monga. We usually have this as a joint Nevada andCalifornia BBQ, sometimes we are suprised whena car pool from Arizona shows up. This year Wolf-gang Snitsar KV4ATV and his son Vlad will be toCalifornia to attend. Tom has his famous BBQ ribscould this be the reason for such a long trip?

One of the topics of discussion at the upcomingBBQ will be some planning on a microwave link(s)to connect the California/Nevada linked repeatersto the linked Arizona ATV repeaters. The most di-rect path is via Hayden Peak. See map below.

The two green paths on the map, Snow Peak toHayden and Hayden to White Tank are the longestbut most direct.

Our repeaters are working but we have a QRMissue to the link receiver at Mt. Wilson on 5910MHz FM. A few months back black lines showedup in the picture but are constant but otherwiselook similar to RADAR. Merv Hecht KO6E madea donation for our purchase of an RF shield (somecall it a shroud) to improve the front to side ratio ofthe RX dish at Mt. Wilson. We plan to make someadjustments to it so it will fit the existing dish,Thank you Merv!.

We plan to visit Mt. Potosi for some adjustments tothe 1253.25 MHz exciter and add a video proc am-plifier for some added sync level. The rest of therepeaters are in good shape and only need acheck before next winter.

This spring was a sad time for our members, welost Mike Moranta KC6YNQ in late April due to abad case of the flu he could not recover from.

Mike (L) & Roger (R) at the ATN-CA WinterMeeting two months earlier.

In May we lost Roger Berchtold WB6HMW to nat-ural causes. Both were long time members andhelped at the sites and with net control whenRoland was not available to run the net. Roger wasat Ord Mountain with Mike Collis WA6SVT the Sat-urday before passing. Both families invited all ATNmembers to attend celebration of life on the sameSaturday with Mike’s in the morning and Roger’sin the afternoon. They both will be sorely missed.

Interested in that ATN look? Mike Collis WA6SVTplans to put an ATN shirt and jacket order together.sizes from small through XXXL. Shirts are Polostyle and have a pocket, can be ordered without apocket too, color is Royal Blue with White printingor our older style White with Royal Blue printing.Jackets are Royal Blue with White printing, linedwind breaker style. Name and call sign is embroi-dered as an option. Contact Mike WA6SVT [email protected].


atn summer 2019 newsletter - rollinvideo.com€¦ · atco news activities ... from my work-bench...

Documents