70MHz Trophy

Enthused about 4m from previous outings we decided to visit British (IO81KR) again. We were late starting by 30 minutes by eating cake and coffee before departing to the site!. There was mist/rain/drizzle for the whole contest. Again we used the K3S and the Anglian transverter to drive the I0JXX dualband amplifier. The antenna was the 5 ele Powabeam at 6m,

The only equipment issue was computer related. The K3S just has one USB connection to the computer (no audio leads). For the first 30 minutes on every speech peak the virtual serial port and the K3S soundcards would be removed from the computer and reappear on receive. After a while there was a warning that the device was disabled as it was unstable. Not having had this issue on previous 4m events I took a look at the USB lead. I had taken the first one from the bag; a thin black lead. Looking further I found a thicker lead with clear cover that showed a decent braid. Changing to that cable, the issue went away!
In a change to  normal, there were numerous stations QRV up north, in IO84 and 94. This activity allowed us to confirm that the site is good to the North, we dont normally work much up there as there is no activity! The loudest signal was from GM4ZUK/P in IO86. Although two stations were worked in GU, there was not even a hint of a GJ station or GD. Being called by GI4OPH in the last hour was a welcome surprise/ 98 QSOs were had with the best DX being PA4VHF in JO32 at 640km

June 70MHz UKAC

After the success during the previous Sunday's 4m contest, thoughts turned to the 4m UKAC the following Tuesday evening. Blorenge is much more hospitable at this time of week and it was much easier to get to directly after work than British Mountain

This time we used Rogers Van to support the 5 ele Powabeam at 20' Again the K3S drove the Anglian transverter then the I0JXX amplifier module, all operated from the Honda Jazz.

There was some DX heard while setting up from EA and IC8, but it disappeared as the contest started. Conditions on tropo were poor, but we ploughed on, listening around between qsos. We found EA6SX who we worked at 1442km as the best DX. After this excitement the search for multipliers continued. No continental DX was worked. Northern English squares were well represented but despite calling a lot that way, there were no sign of GM stations. 109 QSOS were made in total

Nice Sunset

Postscript
The results have been published very speedily... within 12 hours of the entry deadline, AND the writeup contained more details than "the next contest is on xx/xx/2016! Looks like only our station worked the Sporadic-E

Pos	Callsign UBNs	Loc	QSOS	Score	Mults	Total	Norm	ODX	Kms	Power
1	GW4FRE/P	IO81LS	107	19,874	34	675,716	1,000	EA6SX	1,442	150
2	G4FZN/P	IO94JF	101	17,875	32	572,000	968	G3VXM	381	160
3	G3TCU/P	IO91RF	84	13,577	32	434,464	935	GM4NFC	530	160

70MHz Cumulative Contest

Having finally  finished integrating my I0JXX dual band 50/70MHz amplifier it needed trying out. The contest calendar showed a 2 hour 4m (2nd cumulative) contest so we decided to give it a try. Blorenge is no place to be on a Bank holiday Sunday so an alternative was needed. Roger suggested British Mountain which was a bit more remote. I had never been there so I went there via his house, so i could follow him. The route was challenging for both vehicles. As we neared the destination we noted a vertical antenna and a tent, which caused concern, Dropping by and introducing ourselves we found they were CBers so we should have no trouble to us on 70MHz. We moved 100m along the road and setup the station. The 5 element Powabeam was put on 25' of pole with guys. The rest of the station was the K3S (on its first outing) and my G4DDK Anglian Transverter. We also got to try the audio boxes I had made which allows the operator and logger to choose any combination of main and sub RX audio

When the antenna was connected the band was full of wideband signals. Sporadic-E was in progress, the band was occupied by FM broadcast stations from Eastern Europe. SQ8EP was worked before the contest, but during the contest, despite the broadcast SP-E signals there was no SP-E dx available, the best dx was PF7M. The Northern English squares were well represented but despite calling a lot that way there were no sign of GM stations. 71 QSOS were made in total.

Postcript:

A friend of a friend stumbled across a youtube video from visitors to the CB station wondering what was going on at the white van up the road from the cb station! The video is here  https://www.youtube.com/watch?v=jJ5Bs29CXGY   The marauding sheep timestamp the recording time

PA checkout day

Provoked by an email by G4BVY after borrowing his 1kW 30dB Bird Tenulune I decided it was time to test out some amplifiers

First up was my Elecraft KPA500. It still had the old V1.11 software so this was upgraded to 2.23. It was then tested out and worked fine, a good tryout in preparation for this weekends ARRL RTTY contest

Next up was the 70MHz amplifier. Previously I had acquired a DEMI 48V 50MHz 300W PA. As the KPA500 gives me 500w on 6m it was decided to put it on 4m. Steve told me the only thing that would need changing is the low pass filter. Looking in the junkbox and finding some UNELCO caps and some 2mm silver plated wire one was built and installed.

Next a 48V power supply was needed. I had bought an Erskine one from Jim GI1CET on ebay (I first saw them when he had them at the EME2012 conference but was too late to get one) Unfortunately it produced 54V, bit high for the amplifier. Using the instructions provided,  the cover and sisterboard were removed and a 220k resistor put in parallel with the 22k resistor to the right of the voltage set pot. This gave me the 47-50V range which was ideal

Hooking up the PA to the output of the DEMI 70MHz xverter (configured so that whatever i did it could only run 10W maximum, rather than its normal 35W) 8W gave me 370W on 4m . A quick test showed that it still gave 400W  on 6m for 6W of drive, both of which were acceptable

HPSDR on 70MHz WSPR again

Overnight I remembered that it is possible to control the HPSDR under Cat control. It can emulate the TS-2000. So I went into HPSDR setup and changed Cat control to 4800-N-2 on COM17  and enabled it:-

In the WSPR program under station parameters PTT method was changed to CAT, enable cat was ticked and Kenwood TS-2000 4800-8-N-2, no handshake chosen:-

Remember N8VB VCOM previously set up a virtual com cable between com7 and com17
Now the HPSDR is controlled without DTR etc. WSJT can also control the frequency.
Efforts were rewarded. My signals were heard in Holland:-

2012-12-23 19:12	G4FRE	70.092501	-23	-1	IO82uc	5	PA0O	JO33hg	614	74
2012-12-23 16:08	G4FRE	70.092507	-17	-2	IO82uc	5	PA0O	JO33hg	614	74
2012-12-23 14:56	G4FRE	70.092474	-16	-1	IO82uc	5	PA0O	JO33hg	614	74
2012-12-23 14:22	G4FRE	70.092485	-18	-3	IO82uc	5	PA0O	JO33hg	614	74

And in the UK:-

2012-12-23 15:54	G4FRE	70.092522	-20	0	IO82uc	5	G3SHK	IO90dx	131	162
2012-12-23 12:00	G4FRE	70.092501	-25	-1	IO82uc	5	G0MJI	IO83ni	144	344
2012-12-23 10:32	G4FRE	70.092521	+12	1	IO82uc	5	G3LVP	IO81wv	26	154
2012-12-23 09:24	G4FRE	70.092451	-15	3	IO82uc	5	M0NKA	IO92	95	63

And I heard a signal from Holland:-

2012-12-23 14:02

PA0O

70.092501

-30

-1

JO33hg

50

G4FRE

IO82uc

614

261

HPSDR on 70MHz WSPR

Tonight I decided it was time to work out how to interface the HPSDR to the K1JT WSPR programme and try it on 70MHz. My Penelope board has a -20dB coupler on the output giving 0dBm which is fine for driving my DEMI L70-28 transverter http://downeastmicrowave.com/PDF/VHF-UHFXVERT_pd.pdf (serial number 1!) to 35W maximum. The normal 0.5W output of the Penny board should be terminated in 50 ohms to protect the output stage

I use the W5WC dual RX version of POWERSDR as this allows me two 96kHz chunks of the band to be seen at the same time. Usually one is on the beacons and one is on the calling channel

First I installed my paid for copy of Virtual audio cable which will allow the audio to be connected between the 2 programmes. It was configured to support VAC1 and VAC2.

Next a copy of N8VB's VCOM programme was installed with 2 pairs of cables, COM6>COM16 and COM 7>COM17

In the HPSDR Setup, CAT control TAB the port is set to COM 16, RTS and enabled:-  

Next the VAC setup in HPSDR. VAC1 is setup as VAC2 as the input and VAC1 as the output:-

Next the WSPR programme needed setting. Audio IN is set to VAC1 and audio OUT is set to VAC2. Note these settings are the REVERSE of the HPSDR ones

Drive level to the transverter was set to produce 5W output. The 10MHz reference for the HPSDR was produced by a Thunderbolt GPS unit,  which also, with the help of KE5FX "Lady Heather" Monitoring programme http://www.ke5fx.com/heather/readme.htm was used to set the computer clock every 15 minutes. The 70/28MHz transverter Local Oscillator is not yet GPS locked; an upcoming project based on the G4HUP DFS design

The system was allowed to run whilst packing the Christmas Candy

Looking at the WSPRNET spot database http://wsprnet.org/drupal/wsprnet/spots it was pleasing to see the signal had been seen:-

2012-12-22 22:16	G4FRE	70.092565	-15	0	IO82uc	5	M0NKA	IO92	95	63
2012-12-22 22:16	G4FRE	70.092534	-22	-1	IO82uc	5	PA0TBR	JO22pi	517	84

The PA0BTR spot was the ODX for the days spots on 4m; not bad for my Indoor Halo!