Posts Tagged ‘2m’

March Moonbounce


Tied up with other radio happenings, I missed getting on EME during the moon's last two orbits of the planet. I was able to get back at it last week, with three days of unobstructed ocean moonrises as the moon travelled through its northern declination peak.

Conditions seemed unusually good and I was able to complete several contacts with my small station ... a single 9el m2 Yagi and an older 2m 140W brick amplifier. The Yagi is nestled atop my 50' tower's mast, between my triband Yagi, and Yagis for 6m and 70cm. The tower is located about 100' from the ocean and on these favorable moonrises, looks towards the moon directly over saltwater. The antenna appears to develop the full 'theoretical' 6db of seagain and performance seems fairly similar to what I would expect from a box of four similar Yagis.

Stations worked last week (all on JT65B) where: I3MEK, K9MRI, PA0JMV, WA3QPX, G4DML, EA5SR, and SP8NR. The first three stations had been previously worked but answered my CQ while the remainder where all new, representing 'initials' #84 - #87 using this simple system.

WA3QPX 4 X 28 el Yagi array

EA8SR's 4 X 9el Yagi array


G4DML's 4 X 8el Yagi array


K9MRI's monster array - 8 x 28el Yagis


K9MRI provided the best signal report I had ever received on moonbounce, a -15db and indicated that my signal was audible during our QSO!

WA3QPX represented a new 2m state, which made me wonder what my confirmed state totals had reached ... 26 now, including EME and terrestrial contacts. Interestingly, my 2m DXCC total also stands at this same number ... 26 confirmed.

With such a low ERP, I often think that I will eventually run out of stations that I can work on EME, yet I continue to see many new stations every time I get on the air ... likely enough to keep me challenged for some time yet.

I often hear stations better than they are hearing me so if I do run out of stations, the next logical step would be a modest 3db increase in my power by building a simple 300W amplifier. An extra 3db would probably open up a large number of new challenging target stations to work with.

I have a box of NIB 4CX250Bs and sockets that have been looking at me longingly for some time!

EME In The ’80s

VE7SL - my original 2m EME antenna.
My recent round of 2m moonbounce activity reminded me of how much this mode has changed over the years. Back in the early 80's I decided that building a 2m eme system would be a good project for winter evenings and would keep me out of trouble for a few years. Back then, it was all CW, with a smattering of SSB reserved only for the big-boys.

Unlike today's widespread JT65B usage on eme, where signals can be many db into the noise and inaudible by ear, eme contacts could only be completed by actually copying signals that you could hear with your ears. This usually required big antennas and lots of power.

After a year and a half of evening work in my basement shop, my system was pretty much ready to go. I built a kilowatt amplifier, from the ARRL's VHF Handbook, along with its plate and screen power supplies.

2m 'Plumbers Delight' handbook amp.
The amplifier used a pair of 4CX250Rs ... a very popular tube to use then and readily available. The amplifier, when run in class-C, would put out nearly a kilowatt. All of the parts were reclaimed from surplus, purchased inexpensively at our local, long gone, 'Satellite Surplus' store on Vancouver's Main Street ... this was a goldmine of radio-only parts. Pete, the proprietor, was a real character. He had a good eye for a bargain and would buy government surplus lots of equipment and strip them for parts. He must have been well-connected as the place was full of gems ... but one dare not try and argue about prices! I saw more than one guy kicked-out for trying to work Pete down a few bucks.

My antennas (see above), as well as the large H-frame support, were also built in the basement and used all scrap aluminum from one of the numerous scrap yards that were in Vancouver at the time. The system consisted of sixteen separate 6 element NBS-styled yagis, all phased. Many of the two-dozen plus N connectors were bought at Boeing Surplus near Seattle, another interesting source of parts, also now long gone. Keeping water out of the phasing lines and connectors was a real challenge here in the rain forest and if one connector was not done exactly right, would create a lot of headaches.

The antenna took up a large portion of my small, 33'-wide suburban backyard. Pointing was all done by hand, using homemade scales to indicate elevation and azimuth angles, so that it could be pointed accurately even on cloud covered days and nights. A hand-cranked boat winch took care of elevation. I had a switch-box full of surplus VHF relays out at the antenna that protected my JFET preamp and also allowed me to compare sky and sun noise against a 50 ohm load.

Over the course of a few years, the system was employed to work many Europeans as well as North American VEs' and Ws'. The one contact that stands out memorable for me, was with UA3TCF, east of Moscow. This was because I had to aim the array directly into my two-story house, located about 20' away! The moon was very low as well, so that not much elevation was required.



I eventually found that trying to hold down a full-time high school teaching job and running sked requests at 0300 were not very compatible! It also became a lot of work just to maintain the system properly. I had met and completed my original goals and it became time to move on.

Eventually the array was broken down into smaller sections and sold to local 2m guys, along with the amplifier ... but it was a huge learning experience for me and the fact that I survived building and playing with a 2,000 volt power supply, still scares the heck out of me!

Plate & screen supply for the 2m amp.

The VHF rack with xvrtrs and amps 50mHz-432mHz.

My gal Sal adorning the 2m tower on a snowy Sunday morning.

EME In The ’80s

VE7SL - my original 2m EME antenna.
My recent round of 2m moonbounce activity reminded me of how much this mode has changed over the years. Back in the early 80's I decided that building a 2m eme system would be a good project for winter evenings and would keep me out of trouble for a few years. Back then, it was all CW, with a smattering of SSB reserved only for the big-boys.

Unlike today's widespread JT65B usage on eme, where signals can be many db into the noise and inaudible by ear, eme contacts could only be completed by actually copying signals that you could hear with your ears. This usually required big antennas and lots of power.

After a year and a half of evening work in my basement shop, my system was pretty much ready to go. I built a kilowatt amplifier, from the ARRL's VHF Handbook, along with its plate and screen power supplies.

2m 'Plumbers Delight' handbook amp.
The amplifier used a pair of 4CX250Rs ... a very popular tube to use then and readily available. The amplifier, when run in class-C, would put out nearly a kilowatt. All of the parts were reclaimed from surplus, purchased inexpensively at our local, long gone, 'Satellite Surplus' store on Vancouver's Main Street ... this was a goldmine of radio-only parts. Pete, the proprietor, was a real character. He had a good eye for a bargain and would buy government surplus lots of equipment and strip them for parts. He must have been well-connected as the place was full of gems ... but one dare not try and argue about prices! I saw more than one guy kicked-out for trying to work Pete down a few bucks.

My antennas (see above), as well as the large H-frame support, were also built in the basement and used all scrap aluminum from one of the numerous scrap yards that were in Vancouver at the time. The system consisted of sixteen separate 6 element NBS-styled yagis, all phased. Many of the two-dozen plus N connectors were bought at Boeing Surplus near Seattle, another interesting source of parts, also now long gone. Keeping water out of the phasing lines and connectors was a real challenge here in the rain forest and if one connector was not done exactly right, would create a lot of headaches.

The antenna took up a large portion of my small, 33'-wide suburban backyard. Pointing was all done by hand, using homemade scales to indicate elevation and azimuth angles, so that it could be pointed accurately even on cloud covered days and nights. A hand-cranked boat winch took care of elevation. I had a switch-box full of surplus VHF relays out at the antenna that protected my JFET preamp and also allowed me to compare sky and sun noise against a 50 ohm load.

Over the course of a few years, the system was employed to work many Europeans as well as North American VEs' and Ws'. The one contact that stands out memorable for me, was with UA3TCF, east of Moscow. This was because I had to aim the array directly into my two-story house, located about 20' away! The moon was very low as well, so that not much elevation was required.



I eventually found that trying to hold down a full-time high school teaching job and running sked requests at 0300 were not very compatible! It also became a lot of work just to maintain the system properly. I had met and completed my original goals and it became time to move on.

Eventually the array was broken down into smaller sections and sold to local 2m guys, along with the amplifier ... but it was a huge learning experience for me and the fact that I survived building and playing with a 2,000 volt power supply, still scares the heck out of me!

Plate & screen supply for the 2m amp.

The VHF rack with xvrtrs and amps 50mHz-432mHz.

My gal Sal adorning the 2m tower on a snowy Sunday morning.

Thursday’s Moonrise



I couldn't hold out any longer! The sight of a full-moon rising over the ocean a few nights ago was just too difficult to resist ... I would have to spark-up my 2m mini moonbounce system and see what was happening.






The QSLs are now all in from my last eme adventures in the early summer, bringing my total number of contacts to 80.




RW1AY used an 8 x 15el cross-polarized array

EA4CQ's 4 x 9el DK4ZB yagis

YU7AA's 8 x 13el nested array

NC2V used a 4 x 20el cross-polarized array

VE1KG's 4 x 17el yagi array


DK5SO used four 20' long yagis and 750W

My simple system uses a single 9el m2 yagi and an old third-hand 140W brick amplifier and built-in GaAsFET preamp. The yagi is mounted atop my 50' tower and fed with about 100' of RG-213 cable, along with its 2+ db of loss.

Looking directly out over the saltwater of Georgia Strait seems to provide the near theoretical 'sea-gain' of 6db, making the little yagi behave more like a box of four in terms of gain. As well, there are no noise sources when pointing out over the water at the rising moon. Not being able to elevate the antenna means 'moonrises' only, and usually gives me about 90 minutes per session before the moon gets too high.

Last night was surprisingly active, mostly with U.S. stations, as it was still early evening here but there were also several early-rising Europeans on the band.

One outstanding signal was from a station I had not worked before, OK1DIG, who was running a 4 x 15 element yagi array. I called him a few times when his signal was easily audible (-15db) but he seemed to only hear me later, replying to one of my 'CQ's, with his signal starting to drop here. This is often the case on 2m eme as a reciprocal two-way path is not always the rule. He was my only contact of the evening (#81) but also heard were K9SLQ, UT3MD, PA3FYC, all of whom I have yet to work.

OK1DIG's audible JT65B CQs
With another favorable moonrise tonight, albeit over an hour later, another go will be hard to resist!

Thursday’s Moonrise



I couldn't hold out any longer! The sight of a full-moon rising over the ocean a few nights ago was just too difficult to resist ... I would have to spark-up my 2m mini moonbounce system and see what was happening.






The QSLs are now all in from my last eme adventures in the early summer, bringing my total number of contacts to 80.




RW1AY used an 8 x 15el cross-polarized array

EA4CQ's 4 x 9el DK4ZB yagis

YU7AA's 8 x 13el nested array

NC2V used a 4 x 20el cross-polarized array

VE1KG's 4 x 17el yagi array


DK5SO used four 20' long yagis and 750W

My simple system uses a single 9el m2 yagi and an old third-hand 140W brick amplifier and built-in GaAsFET preamp. The yagi is mounted atop my 50' tower and fed with about 100' of RG-213 cable, along with its 2+ db of loss.

Looking directly out over the saltwater of Georgia Strait seems to provide the near theoretical 'sea-gain' of 6db, making the little yagi behave more like a box of four in terms of gain. As well, there are no noise sources when pointing out over the water at the rising moon. Not being able to elevate the antenna means 'moonrises' only, and usually gives me about 90 minutes per session before the moon gets too high.

Last night was surprisingly active, mostly with U.S. stations, as it was still early evening here but there were also several early-rising Europeans on the band.

One outstanding signal was from a station I had not worked before, OK1DIG, who was running a 4 x 15 element yagi array. I called him a few times when his signal was easily audible (-15db) but he seemed to only hear me later, replying to one of my 'CQ's, with his signal starting to drop here. This is often the case on 2m eme as a reciprocal two-way path is not always the rule. He was my only contact of the evening (#81) but also heard were K9SLQ, UT3MD, PA3FYC, all of whom I have yet to work.

OK1DIG's audible JT65B CQs
With another favorable moonrise tonight, albeit over an hour later, another go will be hard to resist!

6m Awakens

Well Friday morning's planned 2m EME window got pushed to the side when 6m started to show some interesting propagation possibilities. Several Europeans had been working slowly westward, past their usual east coast stopping point. When EA8DBM (Alex) in the Canary Islands reported via the ON4KST 6m chat page that he was hearing a station in Montana, my ears really perked up. At around 10:30 local time, KE7V (Johnny), about 40 miles due south of me in Washington state, was heard working Alex but I could hear nothing from him at all.

As is often the case between here and KE7V, signals from Europe often move quickly northward and sure enough, about two minutes later, EA8DBM's CW signal appeared at good strength, calling CQ.


I quickly worked Alex, whose signal stayed around for almost an hour, and then began looking for any others that might be riding along on the same path. Sure enough, his neighbour, EA8TL was heard CQ'ing, but much weaker. After a few calls he came back with my report to which I responded several times, but it was evident that he was having difficulty as he kept repeating my report. Unfortunately, and unlike Alex, he soon faded away without me ever hearing the needed 'RR' for my signal report confirmation.

About an hour later, a rapidly fading and quickly building signal was heard on CW calling CQ at about 25wpm ... it was CN8KD in Rabat, Morocco!

courtesy: https://www.google.ca/maps/
It's times like this that 6m demonstrates why it's called the 'magic band', as exciting moments like this are so rare on the west coast ... the very thing that keeps us 6m nuts glued to the radio during the summer months.

I called Mohamed several times as his signal built, but his rapid-fire CQ's continued much to my frustration. As his signal peaked to a solid 569, he sent a '?' and then replied with 'VE6?', probably as shocked as I was. After repeating my call several times, he returned once again but this time with 'VE7NL?'. The next several transmissions from him were the same and as the delicate links between our two stations shifted once again, he was gone as quickly as he'd arrived ... close, but no cigar. This was the first 6m signal that I've ever heard from continental Africa since coming on the band in 1970. I wonder if I will ever hear him again.

With a dead 6m band on Saturday morning, I was able to get back on EME (JT65B mode) for my final day of favorable moonrise windows and had a nice surprise when VE1KG in Nova Scotia answered my first CQ, for initial #81 with my small station ...


                          ... all-in-all, a pretty fun week on the VHF's!


June’s EME Moonrise Window



With the QSL's from spring's EME activity gradually showing up in the mail, June's EME moonrise action should keep the postman busy next month as well.

Dmitrij - UA3PTW - Initial #60

Vlad - RZ3BA/1 - Initial #61


Oleg, UX5UL - Initial #72


Val - UT6UG - Initial #73 ...both Oleg & Val are in the same city



Jorg - DK3WG - Initial #74


Bernie - ZS4TX - Initial #75

I have about five days of favorable moonrises directly over the ocean in front of my antenna (9el m2 Yagi), and a couple of hours each day before the moon gets too high for my antenna as it lacks any elevation control. After five days the moonrises usually move too far to the south and I am pointing into too many RF-absorbing Douglas Firs on my neighbor's property.

I started on Tuesday morning, which according the EME data graph shown below, should have been the best of the week since the moon was as close as it would get and the skynoise was low but unexpectedly, no signals at all were heard!

courtesy: http://www.mmmonvhf.de/eme.php

On Wednesday, things should not have been as favorable since the moon was another 5000 miles further away, but the magic of radio did not disappoint ... my first CQ, with the moon barely 1 degree high, brought something that has never occurred here before ... three replies!

I soon completed three new initials with my QRP (140 watts) station ... RW1AY (# 76 ), DK3BU (#77 ) and DK5SO (#78 ). I have no idea why Tuesday was so poor or why Wednesday was so good, but I'll take it.

Today's conditions were also good again, with my first CQ being answered by N2CV in Florida, for #79.


Barry - NC2V - Initial #79  4 x 20 el array

About an hour later, the strong CQ of YU7AA was heard who responded to my first call. After that his signal faded for some time and eventually returned to speaker quality level and the contact was completed for #80 ... I keep wondering if or when I'll run out of stations large enough to work.


Jozef - YU7AA - Initial #80

Who knows what tomorrow will bring, but as the moon climbs further away and rises further to the south, working anyone will be a nice surprise. I've usually avoided summer EME work, as often the best moonrises are very close to the sunrise, making it difficult for bigger stations to hear me when pointing near the sun. After June's good luck, it seems that summers might require more attention ... the next few months might be more interesting than I had thought.

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