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Mother Neff State Park

March 28, 2014, 8:59 pm
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It was time, after a 5 year absence for a trip to the Belton hamfest.  Rather than rush down and back on Saturday I decided to go down on Friday and visit another state park on the way. I chose the Mother Neff State park SW of Waco and NW of Temple. The trip down I35 was uneventful,Lunch was taken In Waco then the route west was started. Immediately thunder, lightening and hail started! There was a lot of ground water when I got to the Park. Putting $2 admission in the honesty box I followed the ridge and found a parking spot. At which point the clouds went away and the sun came out. I planted the PAC-12 antenna with the 10m coil next to the car and called a few stations with the 5W CW from the KX3. I had 10 QSOs with JA, F, FG, DL, the only escapees were a DU and VK4. Being sprint a group of brilliant red red cardinals put on a display, as did the hawk that sat on the fence next to the antenna trying to work out what It was. Time for tourism so I went and looked at the cave on the way out. The warden, having observed my "paid" sticker was closing the access gate at 1630pm but she gave me the combination so I could escape at 1900, giving me just time for Dinner after the HPSDR Teamspeak session at 2000


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Belton Hamfest

March 29, 2014, 9:03 pm
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I havent been to Belton for 5 years so It would be Interesting to see any changes. Despite threats of 81F temperatures on Saturday It was very cold at 0645 when I set off,  I can assure you. The location has been spruced up since the last visit but the hamfest still takes place in and around the drive in "barn" (The other half was being used for dressage lessons!)
Escorted by Roger N5PGH we found some interesting items. He bought an IC215 for (the FM cousin of the IC202) for $50 and a TS120V VFO for $20. I bought 50' of RG58 (for a 1296 preamp power cable) for $3, a 5A RF ammeter for $1 3/6/10dB mini circuits 1.5GHz attenuators at $2 and a 28V 52A PSU for $60. I Had an interesting conversation with its seller about the 12V Power One power supply also on his table which was a relative of the one I was experimenting with last weekend.
I was looking for a butterfly capacitor to make a remotely tunable version of the Alexloop. The 1st flea market spot, I found one. A bit dirty but .04" plate spacing 2 x 220pF. When I asked the price the owner presented it to me.  "enjoy"!
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Lake Whitney State Park

March 29, 2014, 9:44 pm
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After leaving Belton, rather than rush straight home I decided to go via the Lake Whitney state park. On the way up I35, on the north side of Waco I found the Colin Street Bakery cafe (the factory is in Corsicana...off the beaten track), so It was time for coffee and cake for lunch
Continuing on in glorious sunshine (yes the promised heat did arrive) the park was reached at 1400.  Paying the $5 admission I first explored the (closed) launch ramp but the ground surrounding the car park was too rocky to get the antenna base in. I moved to the area near the swim zone (noone was swimming ) and managed to erect the PAC-12 antenna with 4 radials. Again starting on 10m the SWR was at 1.5:1.



The CQWW WPX SSB contest was in full flow, but 5W to an 8' vertical doesnt stand a chance amongst the big signals and intermods on the band. (eg VK4KW was 59+20 on the vertical but the most response I got during 20 mins of calling was "WW2?" twice!  I struggled to work 10 stations in EA, LU, OH, VE6, VE7, W6 and W7. I tried fitting the 15m and 20m coils but those bands were not much better So I decided to give in and go for a walk round the lake trail. It was very obvious the Lake water level was low:-


 Rather than returning directly up I35E I took highway 77 (which runs parallel to I35E)  which goes through Hillsboro TX, Paris, TX (home of the concrete igloos) and Waxahachie (which promised BBQ downtown but had ran out!) before eventually getting on I35E and making it home.
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Strange conditions on 10m WSPR Saturday 26 April

April 27, 2014, 7:09 am
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While doing some other tasks on Saturday I let my Ultimate 3 transmitter run for the whole day from 1200z at 1W output with the help of an external PA. The results were very strange. Nothing, then lots of Oceania with a few Americans at the start:-

TimestampCallMHzSNRDriftGridPwrReporterRGridkmaz
2014-04-27 02:30 WW2R 28.126119 -21 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 02:12 WW2R 28.126093 -17 0 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 02:12 WW2R 28.126119 -26 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 02:00 WW2R 28.126077 -23 1 EM13pc 1 VK5ST PF95ml 14929 252
2014-04-27 01:48 WW2R 28.126104 -16 0 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-27 01:48 WW2R 28.126119 -26 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 01:36 WW2R 28.126077 -16 1 EM13pc 1 VK5ST PF95ml 14929 252
2014-04-27 01:36 WW2R 28.126093 -26 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 01:30 WW2R 28.126096 -26 0 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 01:30 WW2R 28.126119 -21 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 01:30 WW2R 28.126104 -17 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-27 01:30 WW2R 28.126093 -23 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 01:18 WW2R 28.126104 -16 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-27 01:12 WW2R 28.126103 -13 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-27 01:12 WW2R 28.126092 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 01:12 WW2R 28.126118 -20 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 01:00 WW2R 28.126098 -27 0 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 01:00 WW2R 28.126096 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 00:54 WW2R 28.126119 -26 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:54 WW2R 28.126093 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 00:54 WW2R 28.126096 -23 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:48 WW2R 28.126097 -19 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:48 WW2R 28.126120 -19 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:48 WW2R 28.126105 -13 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-27 00:42 WW2R 28.126120 -19 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:42 WW2R 28.126096 -17 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:36 WW2R 28.126093 -22 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 00:36 WW2R 28.126095 -24 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:36 WW2R 28.126118 -17 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:18 WW2R 28.126120 -19 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:18 WW2R 28.126096 -21 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:18 WW2R 28.126093 -24 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-27 00:12 WW2R 28.126121 -20 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-27 00:12 WW2R 28.126098 -20 0 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-27 00:12 WW2R 28.126119 -29 1 EM13pc 1 VK5ADE PF95he 14974 252
2014-04-27 00:12 WW2R 28.126095 -17 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:54 WW2R 28.126119 -20 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:42 WW2R 28.126095 -27 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:42 WW2R 28.126098 -22 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:42 WW2R 28.126120 -17 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:36 WW2R 28.126121 -22 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:36 WW2R 28.126096 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:36 WW2R 28.126099 -23 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:36 WW2R 28.126104 -18 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-26 23:30 WW2R 28.126097 -15 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:30 WW2R 28.126102 -16 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-26 23:30 WW2R 28.126117 -23 1 EM13pc 1 VK5ADE PF95he 14974 252
2014-04-26 23:30 WW2R 28.126093 -27 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:30 WW2R 28.126120 -16 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:24 WW2R 28.126121 -11 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:24 WW2R 28.126099 -18 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:24 WW2R 28.126096 -28 0 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:18 WW2R 28.126094 -23 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:18 WW2R 28.126102 -12 1 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-26 23:18 WW2R 28.126097 -21 1 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:12 WW2R 28.126119 -14 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:12 WW2R 28.126092 -24 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:12 WW2R 28.126096 -25 0 EM13pc 1 VK5EI PF95gc 14984 252
2014-04-26 23:06 WW2R 28.126122 -14 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 23:06 WW2R 28.126095 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 23:00 WW2R 28.126093 -26 0 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:54 WW2R 28.126096 -17 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:54 WW2R 28.126103 -25 -1 EM13pc 1 VK3DXE QF21nv 14500 246
2014-04-26 22:54 WW2R 28.126123 -15 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 22:42 WW2R 28.126096 -27 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:42 WW2R 28.126114 -21 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 22:36 WW2R 28.126104 -13 0 EM13pc 1 ZL1AML RF73gb 12040 237
2014-04-26 22:36 WW2R 28.126096 -26 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:36 WW2R 28.126114 -11 1 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 22:24 WW2R 28.126094 -25 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:24 WW2R 28.126099 -23 0 EM13pc 1 K9AN EN50wc 1091 42
2014-04-26 22:24 WW2R 28.126148 -13 0 EM13pc 1 N9XY EM84ml 1279 79
2014-04-26 22:24 WW2R 28.126112 -18 0 EM13pc 1 VK3AMW QF22ir 14513 247
2014-04-26 22:18 WW2R 28.126147 -19 1 EM13pc 1 N9XY EM84ml 1279 79
2014-04-26 22:12 WW2R 28.126150 -23 0 EM13pc 1 N9XY EM84ml 1279 79
2014-04-26 22:06 WW2R 28.126096 -20 0 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 22:00 WW2R 28.126099 -23 0 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 21:54 WW2R 28.126098 -20 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 21:48 WW2R 28.126099 -26 1 EM13pc 1 VK4ZBV QG62ml 13413 255
2014-04-26 19:36 WW2R 28.126098 -23 1 EM13pc 1 WP4JT FK68 3368 111
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Blast from the past!

April 13, 2014, 6:09 pm
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As is usual at the time of year I persuaded Roger G4BVY to go out locally to Malvern to do the 6m contest operating as usual as G4BVY/P. Conditions were not as good as last year, but while I was  operating, I was called by G4AEH, who was surprised that G4BVY/P knew his name, that is was until I told him I was operating! Why was the call so memorable?G4AEH was the reason I took up amateur radio and this was our 1st ever QSO!
 
At school I was interested in medium Wave DXing. I had a Fidelity Rad12 portable ( I couldnt afford a HAC One tube Short wave set) that heard a lot of DX stations (especially after I worked out how to connect a long wire to it). However one Sunday morning I was surprised to hear one side of a conversation with somone signing G3YTW in the middle of the Medium wave band.  I remembered that at school (King Edward VI Grammar school, Nuneaton:KEGS) there was a Prefect who I had heard was into Ham Radio. So I plucked up courage ( needed as he was a prefect and many years older than me!) and asked him what was going on. He very carefully explained it was a 455kHz image from the 160m band that was mixing to the medium wave band, G3YTW wasnt actually transmitting on Medium Waves. He also answered a whole load of associated questions. He invited me to see his 160m station which started my Interest in amateur radio.
 
In my 4th year (1974) I attended an RAE class one night a week at the local technical college G3YLG  This needed written consent from my headmaster R.P. Brown as it was the same year as "O" level exams and they were worried about distraction but he thought a "non critical" (to him) would be good. This was the days when the RAE had essay questions, as can be see by the 1974 paper All went well and I got an RAE pass. As I was underage my Parents had to countersign the application. My father would not sign it until i built a lockable box to secure my Pye Cambridge 2m rig from my brothers and sisters . I built a substantial one out of 3/4" chipboard. It lasted a long time, much longer than the Cambridge; I only threw it out when moving out of the Mckinney house in 2012, I was using it to store waveguide components. Impressed he signed the form and I was issued G8JMO, which being VHF only started my long interest in those bands
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Wimo 2344 1296MHz Yagi: VERY Impressed!

April 16, 2014, 6:07 pm
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Last year for the April UKAC 23cm contest I used a 23 element F9FT. AS the 10W section restricts one to a single Antenna I decided to look at higher gain alternatives, preferably more robust and sunlight stable.

Talking around a few suggested a Wimo Yagis. Looking at their web site the choice came down to a 3m long 44 ele (2344)  and a 5m 67ele (2367). I did look at getting the 67 ele for eme but only using part of it for tropo, but the mechanics did not cooperate, so I ordered the 44 ele. The credit card transaction was done via the link they supplied but the transaction was rejected by NatWest. I had to speak to them and authorise payment to Wimo as they thought it was an Eastern European scam account!

The antenna arrived in three days and was VERY well packed, It had to be jemmied out of the package! It assembled easily in under 20 minutes without needing any adjustment (unlike the F9FT 23 ele which needed the boom deburring and the sub-boom holes redrilling in the correct locations) The elements are premounted and it didnt need the 60 minutes to centralise the elements in the plastic holders. German engineering at its best!  Mounting it on a pole in the garden the return loss was measured. 25dB was obtained without touching anything. I had been told the match can be adjusted  by squeezing the driven element but doing this only made it worse so it was left alone.

When dismantled the yagi fits easily in the Honda jazz so it was taken portable in IO81LS again.  It was noticably sharper and had a much better f/b than the Tonna. The portable on Anglesey was almost inuadible off the back of the beam when pointing at JO00 but was a fine signal when the antenna was rotated by 180 degrees

In summary I was most impressed with the Wimo 2344, Pity I did not discover them many years ago!

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MTR2 kit Arrives

May 2, 2014, 7:19 am
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Steve KD1JV is a prolific producer of compact rigs for mountain topping. A few years ago I bought and built an ATS3 and an ATS4 5 band rigs which were great fun, Unfortunately I sold them to finance the KX3.
 
 
My ATS4B
 
I really miss them, so was excited when Steve announced that he was going to do another run of 150 Triband MTR (mountain top radios). The sale was the usual "first come first served" after the web page was launched but I was lucky enough to get one of the kits. Yesterday the kit arrived, wow it is going to be a small rig, makes the KX3 look enormous!:-
 
 
 
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Auto External Reference switching for the ANAN-10 HPSDR

May 7, 2014, 8:02 pm
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Over the period I have owned the Anan-10 SDR Transceiver the only issue for me has been that to use an external 10MHz reference it has to be taken apart and links changed, which runs the risk of damaging the tiny RF cables. Last August G8ONH/G7OCD mentioned on the OpenHPSDR reflector they were working on a small PCB to be mounted in the ANAN-10 that would automatically switch the ANAN-10 to use the external reference when one is plugged in. This week I managed to obtain a board and set about installing it.
The board is very small:-
 
PCB size compared to a quarter
ANAN-10 Innards before Installation
All I had to do was plug the 4 headers into PCB and solder the pins to the PCB:-

PCB after Installation
 
 The 2 ho;es on the PCB are to allow a jumper to be fitted to ground the SMA connector "outer". A header wasn't supplied so I fitted a right angle 2 pin male connector to the PCB and used one of the now "spare" jumpers  on it
 
Jumper block added
 
Including assembling/disassembling the ANAN-10 and putting the board in place it took only 15 minutes to complete. 
 
My Rubidium drives a DEMI 10-4 four way 10MHz splitter. Attenuating the output with 50Ohm attenuators the minimum level to achieve "autoswitch" was -3dBm which is just fine for my setup
Note that when using the board NOTHING needs to be done to the PowerSDR settings to accommodate the board 
 
 
 
 
 
 
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An evening on 474kHz at WH2XES

May 19, 2014, 4:04 pm
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Tonight I went and visited W5LUA to Christen his new experimental licence WH2XES on 475kHz.
 
In preparation I had built a modified Ultimate 3 Transmitter by Hans Summers http://www.hanssummers.com/ultimate3.html  When originally built with the 2N7000 the output spectrum was nasty, especially LF of the output signal so I looked at alternates. I ended up using the filtered sine wave output from the DDS (the original used the square wave output) to drive an ERA2 and a 2N5109 PA from kitsandparts to a lowpass filter. This produced 200mW into 50 ohms.
 
 
Ultimate 3 New output Stages
 
I also built the GW3UEP 100W IRF540 amplifier:-
100WAmp with Arduino Protection circuitry
 and a matching 100W Low Pass Filter to a design by WA1ZMS
 
 
We started the evening with the 200mW on WSPR into AL's 80m dipole with inner and outer strapped together and tuned against ground with an LC network resulting in a 2.8:1 SWR
 
We immediately got reports from the local
 
01:04   WH2XES   0.475722   -12   0   EM13   0.2   WG2XIQ   EM12mp   93km  
01:08   WH2XES   0.475723   -12   0   EM13   0.2   WG2XIQ  
01:12   WH2XES   0.475722   -11   0   EM13   0.2   WG2XIQ  
01:16   WH2XES   0.475722   -12   0   EM13   0.2   WG2XIQ  
01:20   WH2XES   0.475722   -12   0   EM13   0.002   WG2XIQ  
01:24   WH2XES   0.475722   -12   0   EM13   0.002   WG2XIQ  
 
(we adjusted the power to transmit EIRP at 0120)
Enthused we hooked up the PA which started taking a lot of current but was producing lots of output
 
01:32   WH2XES   0.475722   +10   0   EM13   0.002   WG2XIQ   EM12mp   93   175  
01:32   WH2XES   0.475728   -22   0   EM13   0.002   KF5JIA   EM15qe   194   11  
01:32   WH2XES   0.475729   -7   0   EM13   0.002   WG2XXM   EM15lj   213   0
 
(we forgot to adjust the power setting on WSPR) The signal at WG2XIQ increased 22dB and we were heard in OK. Unfortunately on the next transmit period the supply current limited with no output. We hooked up the exciter to the antenna while we investigated
 
  01:48   WH2XES   0.475722   -19   0   EM13   0.002   WG2XIQ
 
The received signal level had dropped 7dB. We noticed the SWR in the shack was now 8.8:1. We let it run while we braved the chiggers in the field to look at the matching unit
      
  01:52   WH2XES   0.475722   -19   0   EM13   0.002   WG2XIQ    
  01:56   WH2XES   0.475722   -20   0   EM13   0.002   WG2XIQ    
  02:00   WH2XES   0.475722   -19   0   EM13   0.002   WG2XIQ    
  02:04   WH2XES   0.475722   -19   0   EM13   0.002   WG2XIQ    
  02:08   WH2XES   0.475722   -20   0   EM13   0.002   WG2XIQ
 
Opening the box we were met with a nasty smell. There were scorch marks on the box and the red enameled wire on the 180uH toroid was now a brown scorched wire
 
 
 
 
Some more work needs to be done on the matching unit! Needless to say the $1.25 IRF540 needed replacing, but they are in stock at the local emporium 
 
 
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N7ART Audrey II 432MHz Amplifier 240V Conversion

May 25, 2014, 9:18 pm
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A week ago I was taking stock of my 432MHz amplifier collection. The one I had used the most was the N7ART Audrey II 2x3CX800A7 amplifier I bought 20 years ago. Steve made a wonderful job of building the amplifiers as the pictures below show. Unfortunately the PA was wired for 110V so couldn't be used in the UK. The 2600V PSU was not an issue as it was wired for 240V. It was time to investigate what would be needed for conversion.
Luckily I still had the original Documents in which Steve gives the part numbers for the 240V components. The relay supply transformer in the amplifier (Triad FD-4-12) was already dual voltage primary so did not need changing. The heater transformer was a Stancor P8857 which being 115V only primary would need changing to a Triad FD-7-16 which would also mean changing the resistor in series with its primary from 20ohm 20W to 150 ohm 20W. The blower was a Dayton 4C446 115V 50/60Hz which would need changing to a Dayton 2C915 230V 50/60Hz. The search was on
 
The Dayton 2C915 is no longer made but I found an equivalent on ebay for $68. Mouser had the FD-7-16 but on 4 week delivery but someone had one on ebay at $10 shipped, so both were bought along with a 150 ohm 30W resistor from the local emporium
 
This weekend the components were installed. The blower had a different shaped outlet flange so some chassis filing was needed but fitted otherwise. The new transformer had different fixing centres which needed to be drilled along with the mounting holes for the new resistor.
 
Top View of amplifier after modification
 
Bottom View of amplifier after modification
  The amplifier is now ready to go on UK mains!
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TF3LJ Power and SWR meter

June 1, 2014, 6:42 am
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Last year I built the TF3LJ Power meter and subsequently gathered the parts to build his Power and SWR meter.  It was time to finish the project.
 
The first consideration was the directional coupler. I remembered I had built one for the ill fated W7IEV project so this was unpacked. The basic unit is rated at 100W and has -40dB coupling for both forward and reverse signals. I found the fixed 20dB BNC attenuators bought for the W7IEV project so that would give -60dB for both forward and reverse signals.
 
I also found the two AD8307 detector boards from the W7IEV project so all I needed was to mount the Teensy 2++ arduino style module on a carrier board and was ready to go.
 
I mounted the modules and an LCD in a 8"x6" x 3" Box. Probably would have gone in a smaller one but it was available. The software was installed from Lofturs Site and all worked smoothly.
 
The software does have the ability to produce an alarm signal when a preset SWR is exceeded. This could be used to Inhibit an amplifier. It is the phono connector on the back panel below.
 
Front Panel View (KX3 into two 50 ohm dummy loads)
 
Inside view. Teensy is on the left then 2 detector modules
 
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Sam Wetterlin Reflection Bridge

June 3, 2014, 7:10 pm
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Having bought a cheap ($20) Chinese reflection bridge off the internet (NOT ebay) which had appalling directivity (10dB), I decided it was time to build my own to be used with my HPSDR VNA.
 
A survey of the internet and some recommendations pointed me at the designs by Sam Wetterlin. There were two possible designs, I chose the three bead balun version (mainly on size grounds) This used a Minicircuits transformer and a ferrite bead Balun. I bought some "TC1-1-13" off ebay but these had a pinout different from the Minicircuits catalogue and didn't work well. N1JEZ provided a couple of the genuine articles from his collection which worked perfectly The rest of the parts were bought from Mouser and I designed the two tiny PCB with 0805 components and had them made by ExpressPCB 
 
Assembly took five minutes. The two PCB are separated by a brass strip which supports the balun.  I had some Glass fibre tape which I used to stop the Balun moving around on the support. I soldered an smt resistor to the PCB as the reference load to save using a 4th SMA for an "external load.
 
 
Complete Reflection Bridge
 
Closer view of the input circuit. The TC1-1-13 is the small square on the right
 
 
Directivity was very good, exceeding 30dB from 0.47MHz to 1GHz, more than adequate for my present needs
 
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NavSpark Arduino compatable GPS receiver

June 4, 2014, 7:29 am
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Before Christmas I saw a posting for NavSpark on the crowd funding site indiegogo.com.  From the web page https://www.indiegogo.com/projects/navspark-arduino-compatible-with-gps-gnss-receiver  "NavSpark is a small, powerful, breadboard-friendly, 32bit development board that is Arduino compatible, with a world class GPS receiver as on-board peripheral, and under $15".  At that price I ordered one, especially as it came with a dual band patch antenna for $19.
 
It arrived last week, the board looking like an Arduino micro with the dual band active antenna.  Heeding the warning that the U-FL connector can only be used a dozen or so times, I mounted the Board and antenna in a plastic box.
 
 

The Arduino IDE, viewing software programming guide and documentation are all at http://navspark.mybigcommerce.com/resources/    The USB chip is by Prologix, the unit appearing as a serial port (defaults to 115200Baud). After installing the drivers and software and putting the receiver out on my south facing balcony, it found GPS and GLONASS satelites
 
 

The map shows the correct relative position of the satellites, but the map is based on Taiwan (where the units are made) and isn't currently changeable. Not surprising the locked satellites are all to the South with the system on a south facing balcony.

 
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Restoration Project Country Belle 1956 Radio

June 6, 2014, 3:37 pm
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Having built a couple of Tube receivers, a local amateur decided it was time for me to move on to a restoration project. As a challenge he presented me with his spare Country Belle Radio #556  made by Guild in 1956. This radio was made to look like the old style wall Telephone, but had a 5 tube medium wave receiver Inside. Taking the earpiece of its rest turns the radio on. The Winding crank is the tuning knob, very neat. It had some hardware missing (a bell, the tuning crank and the earpiece rest) but was electrically complete.
 
The Tubes lineup is the classic "all American Five".  Converter: 12BE6, IF amplifier: 12BA6, Detector and first audio amplifier: 12AV6, Audio power output: 50C5 Rectifier: 35W4. The subtlety of this lineup is that the filament Voltage/Current all add up so you just connect them all in series across the 110V AC (or DC) supply. The 35W4 even has a tap on the filament to drive a dial light (#47)
 
As the radio is transformerless,  for safety I borrowed an Isolation transformer from WA5VJB. When power was applied, all the heaters lit up, there was some noise but no stations could be tuned in. Tracing the circuitry I found that the grid Transformer of the 12BA6 was open circuit. The Inductor was taken apart and the wire mended. Now when powered up stations were loud and clear. I peaked up the 455kHz IF Transformers, noting that each transformer had an upper AND a lower tuning core.
 
Next task was the Hardware. Luckily a friend of a friend had a carcass inn their barn which I was given. The wood work was bad but it had all the missing hardware.
 
The next decision was what do about the woodwork. In the end I decided to sand down all the wood parts (after stripping the fittings) but this removed the Decals. I then sprayed it with Pecan wood stain/Varnish (3 coats). The brass fittings were cleaned with Brasso (which I discovered is sold in the USA) then varnished. It was recommended to spray the other black metal fittings with Black Lacquer, but using it can be challenging. I went to the local Oreilly's autoparts to get some but after explaining what I wanted it for to the Old Guy, he said not to use it but to use Black "Dupli-color Vinyl and Fabric Coating" as It would flake less. This has really worked well
 
I found a source of replacement decals at radiodaze.com These were water based transfers (like I used many years ago for Airfix model aeroplanes) which were a little tricky to apply. When dry the cabinet was sprayed with Varnish
 
When completely reassembled the radio worked fine and looked very nice, even though I say it myself!
 


The restored external view

 

The restored internal Electronics

 
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DrugStore Tube tester...every shack should have one!

June 6, 2014, 3:40 pm
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To help me restore the Country Belle radio I wanted to test the tubes.  I mentioned this to Roger N5PGH at the NTMS Tuesday BBQ meeting. At the next meeting he appeared with a loaner tube tester in the back of his truck. This was a "Seco Electronic Tube Analyser" It was the type often seen in your local USA drugstore in the tube era so you could test the iffy tubes in your radio receiver and they would sell you a replacement. This one had been previously built into a panel but was now mounted on a undersized box.

It has a meter, switch,  variable load resistor and 92 sockets. It came with a manual of what settings to use for each tube.

All the tubes in the country Belle radio passed with flying colours. along with some other 1930 era tubes I had acquired for future projects.

I had been looking for a 6AF11 audion multistage tube for a while. WA5VJB found me one in the Dayton Hamvention fleamarket. The manual had 3 settings for the tube so decided to test it. Two settings produced good pass results of 120 but the third only produced 20, a big fail. Pity! I then remembered that Roger had mentioned the tube tester can be used as a reconditioner by leaving the tube in its test configuration overnight. Worth a try. The next morning the reading was 100, so I let it be for the rest of the day which restored it to a 120 reading. What a great tool, even if it is so large!  
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Hamcom 2014

June 19, 2014, 6:29 am
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June brings the annual Hamcom hamfest to Dallas, which, as always clashed with the ARRL June VHF contest.

As in the last four years I volunteered to help man the Elecraft Booth, this year with Eric WA6HHQ and wife Lerma. Their plane got diverted from DFW to AUS as DFW closed for an hour due to bad weather so we didn't start setting up till 5pm Wednesday. 

The trade show exhibitors this year started earlier at 0800 and officially closed at 1800, making a long day. The new item this year was the PX3 Panadaptor for the KX3.
 
 
 The K3/0 mini was also in evidence, this time using the software from remotehams.com, to control a K3/KAT500/KPA500 in California. It was great fun on the Saturday afternoon listening to the 6m activity in California during the VHF contest.
 The outside flea market was not too exciting. The main purchase was a Layafette tube tester without model number which may need detective work to find the manual for as they rebadged others models.
 
 
 
 I also got some tube bases, some tubes for my BBC studio-E receiver and a multiband whip for the 2m module

I did get to meet John Langridge. KB5NJD who also operates on LF as WG2XIQ and compare notes from WH2XES. Unfortunately I could not get to his talk.
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Restoring an EICO 625 Tube Tester

June 24, 2014, 8:52 pm
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EICO 625 External View
 
A few months ago I was given an EICO 625 Tube tester to try and restore. I found the circuit on the internet and started cleaning it up. It powered up and the line voltage calibrate function worked as described. I then tried a tube and got very strange results when I set the 12 lever switches. I took the lid off and saw one of the rotary switches controlled by the lever switches had a cracked rotor and stator. These are non standard items, and are impossible to replace.  The tester was sold as a kit and the switch was supplied as a preassembled unit. The instrument looked very useful but I would need another "for parts" one to restore it to full working order.
 

The 3P12W Lever switch
Two weeks ago I saw another of these tube testers on Ebay which looked in good condition and was a bargain at the shipped price so I bought it. It arrived well packed. It powered up but the line voltage calibrate function pot was very jumpy. Time to open it up. I spotted that the heater voltage select switch had a contact hanging in free space. The line voltage calibrate pot had a dead spot on its track. The good news was that the 12 section switch worked perfectly so I could get a working unit from the two. I chose to refurbish the ebay unit thereby avoiding having to remove and resolder a 12p 3w switch unit. I swapped the line calibrate pot and the heater voltage switch. . When powered up I was unable to calibrate the line voltage but a couple of tubes tested out but with lower than expected readings 
 
I had heard that resistors from this era have a tendency go high in value, so I decided to measure some. The first one tested was the one calibrating the line voltage. This was supposed to be 95k 5% but measured at 116k. I discovered on the internet a method for setting this resistor and ended up with a 91k + 4k7 5% resistor. The line calibration now worked fine. I then measured a few more resistors and found them high by an average of 12% so I replaced them all. I also replaced the 0.01uF 400V film capacitor used in the leakage test.
 

EICO 625 Internal View (after component replacements)

 
The unit now worked fine and I tested a 50C5, 1T4, 49, 12BA6 and 12BE6 tubes and compared the results with the drugstore tested and got similar pass/fail results.

At this point I replaced the yellowed plastic window over the tube chart roll with some clear plastic sheet from Hobby Lobby, held in place with craft glue
 
Out of interest I also measured the resistors in the canibalised unit. These averaged 15% high. 
 
Now I have my own tube tester the borrowed drug store one can go back to its owner.  
 
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The Lafayette tube tester from Hamcom

June 25, 2014, 5:47 am
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After the success in restoring the Eico Tube tester I decided the next project would be to  investigate the Lafayette Tube tester I obtained at Hamcom.
As previously mentioned it said Lafayette in two places but had no model number on the outside or inside.  They were known for rebadging other manufacturers equipment, so it was time to look at some Tube Tester Pictures on the Internet to see if I could find a match.  After 30 minutes of searching I came across the Accurate Instruments model 157 on Ebay
 
Accurate Instruments Model 157
 
Looks Identical to the Lafayette one:-
 


The Lafayette Tube Tester
A search of the Internet found the model 157 circuit diagram which seemed to match the Lafayette. I also found the tube setting charts so I tried a few tubes which passed on the Drugstore tester but gave "?" on this one. Remembering the resistor issues on the EICO tester I measured the 3 resistors. The 1.8M 5% and 1.8k 1% were very close to the specified value. The circuit showed a 470 ohm resistor but this was found to be marked 300 ohms. When measured It was 390 ohms so it was replaced with a 300 ohm 1W 5% resistor. I also replaced the 0.01uF 400V short test film capacitor. Now the tubes tested as "pass".
This tester is more transportable than the EICO tester and has 10 tube sockets (and 2 tube pin straighteners) compared to the EICO's 8 tube sockets. The only negative point of the Lafayette is that the Filament switch is labeled A through I rather than actually being labeled with the Filament Voltages like the EICO does. I aim to add some extra labels
 

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Intel Galileo: Super charged Arduino

January 20, 2014, 8:13 pm
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Last November I came across the Intel Galileo Board which can be considered as a "Super-charged arduino" For starters it has a 32 bit 400MHz CPU.

Also onboard:-

Ethernet port
Microsd card slot
USB Host Port
USB Device Port
Full PCI Express mini card slot
2nd serial port

Any of these as a shield (Yes Galileo has the connectors for an Arduino shield board) would cost the price of the Galileo.

I ordered one from Mouser Nov 20 for $69.99+shipping. It was on backorder with a delivery date on Jan 19, much the same as everywhere else. I checked with them Jan 6, they were still quoting Jan 19. Checked online Jan 17, delivery slipped to Feb 10, so I started to look elsewhere! I found Newegg had them in stock for only $59.99 shipped so I ordered one. It arrived 2 days later, great service!

It came with a power supply (with adaptors for different worldwide mains plugs, The quickstart guide had to be downloaded from the Internet (no CD provided)

Managed to load the usual "flash the LED" code and make it work through the IDE. I also managed to programme an AVR needed for another project through the Evilmadscientist.com ISP shield

I ordered a mini PCIe WIFI Card for the next round of experiments, but other projects call!
Galileo Board with Quarter for Scale

With AVR Programming shield

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BeagleBone Black Ubuntu 13.10 with desktop... another UBUNTU FAILURE!!

January 22, 2014, 7:46 am
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Recently I saw that Ubuntu 13.10 was still available. I downloaded ubuntu-saucy-13.10-armhf-3.8.13-bone30.img.xz  from http://www.armhf.com/index.php/boards/beaglebone-black/#precise  unzipped it and wrote the image to an 8GB microsd card using win32diskimager programme on my windows machine

The microsd booted and gave me the welcome and login. (ubuntu, ubuntu) which resulted in the Ubuntu command line prompt. I expanded the file system using the instructions at http://www.armhf.com/index.php/expanding-linux-partitions-part-2-of-2/ to maximise the space available for the desktop. I did another

sudo apt-get update
sudo apt-get install ubuntu-desktop

and off it went installing again.  Four hours later I came back and saw the install was finished and rebooted the BBB and up came the familiar Ubuntu desktop and login prompt. However the mouse cursor was twitching and the video flickering. I typed in the password, moved the mouse and the BBB froze and all the blue LED stopped flashing. I powered off the BBB and repeated the process and it still twitched and froze when the mouse was moved.

I did retry without expanding the file system, same result.I think I will still stick with 12.04 if I want a desktop!!

Just  to make sure of no issues with the BBB I loaded a previously saved 12.04LTE with desktop Image onto a microsd card and booted the BBB and it worked perfectly

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