Dec 042018
 

Wednesday 21st saw the LSWC hold their annual Construction Contest for the Joe Rose Memorial Trophy. Last year saw us two different versions of ATV transmitter. One being for home use including a partly assembled water cooled power amplifier (For an update see below) built by Adrian M0NWK. The second, and also the winner for last year, being a fully portable transceiver in a case built by Jason G7KWP.

Adrian M0NWK

This year Started off with a similar theme. Adrian M0NWK, started off by showing us his Arduino powered controller for a comtech 23cm ATV transmitter.

 

 

 

 

 

 

 

This was achieved by removing the dip switches from the transmitter and replacing them with a SSR (Solid State Relay) board. These relays are then controlled by the Arduino which also shows the selected frequency on the front LCD.

Adrian also showed us the completed Water Cooled Power Amplifier which was shown the previous year. Also shown was an Arduino controlled Temperature monitor.

 

 

 

 

 

 

 

 

Andy G0FVI

Next up was Andy G0FVI. Who has constructed an 80m CW receiver which will eventually become a transceiver in time. By choosing an IF of around 10.695 this allowed him to use bits from numerous scrap 11m radios he had laying around.

 

 

 

 

 

 

 

 

 

 

 

  • The bandpass filter was fabricated from two Toko type ferrite core coils.
  • The first mixer is based around an SA612 chip and also provides amplification. In retrospect this may have been a bad idea as the chip does produce a few ‘birdies’ although they are well below main signal level.
  • The VFO is an Alan Lake design for 80m with the L/C of the tuned circuit changed to give an output of 7.2-7.1 MHz.  Output is buffered in the VFO enclosure and this is fed to the 1st mixer.
  • Output of the 1st mixer is fed to a 10.7 MHz XTAL filter with a bandwidth of about 15-20KHz.
  • The IF amp is based around an MC1350 IC.  Negative DC feedback from following stages provide AGC action (fast/slow).
  • Demodualtion to provide audio out is achieved using a diode ring mixer. Such a mixer provides a nice clean output with little spurious signals. A 10.695 MHz signal is fed into the ring mixer (together with IF).
  • Demodulated audio is fed to a 2 transistor pre-amp which also provides DC feedback for AGC. Audio is sampled at this stage and fed to another transistor amp to drive the signal meter (taken from an 11m walkie talkie!).
  • The audio stage is based on a rather ancient LM380N!

All stages were built and tested using a sig gen/scope etc. before being connected. Great care was taken with the construction of the VFO, whose spectral purity I was finally able to look at using an SDRplay RSP1A and a beta release spectrum analyser app.

Controls are IF (RF) gain, volume, RIT, AGC fast/slow and VFO.

When I complete this I will add a prefabricated board for PA and some TX/RX switching (should just about fit). I will sample VFO and mix with TX XTAL oscillator, add some filtering and off to PA. Might be an idea to have a go at matching XTAL filter in the receiver too.

 

 

 

 

 

 

 

 

 

David G6MAF

Next up was David G6MAF. Who had constructed a RF tap, or signal monitor which covered 2-30MHz. A device like this is very useful for monitoring your own transmissions by connecting straight into the feed line. With 50 ohms through to the antenna from the transmitter, a second output is taken and attenuated for feeding into a device such as a spectrum analyser etc…

 

 

 

 

 

 

 

 

 

Bob G4PDF

For the final item we made full circle as Bob, G4PDF, showed off his portable 5GHz ATV Transceiver. The equipment was all installed in a box which was mounted to the back of the dish which was then fixed to a tri-pod. The transceiver included a screen overlay showing his Callsign and also converted a received GPS signal into a locator which is also displayed.

 

 

 

 

 

 

 

 

 

 

The Winner

It was at this point after all had builds had been shown that contestants left the room for the remaining to vote on who’s they thought was the best. After discussions about complexity, imagination, modules or scratch built & uniqueness, the vote was in.

 

The contestants were called back in and the Winner was…… Bob G4PDF, with his 5GHz ATV.

 

The trophy will be awarded at the clubs AGM.

Jul 172018
 

This weekend was the Boultham Park Summer Fair and the LSWC was there as usual with a demonstration station.

G5FZ/P

out portable… again? Yes it is.

 

With equipment being collected during the week, Les G1LQB, Steve M5ZZZ, Ian G4EVK, Barry G4DBS, Tom G4OSB, Fred G4HNQ, Peter 2E0FGA, Roger G3PVU & Jackie were on site early Saturday morning. Soon Stephen 2E0SSM arrived to help during the day closely followed by Peter, M0EJL and Pam, G4STO with the tables and radios. All then helped in getting the station set up before the Public arrived.

Once everything was set up Pam got the bacon out and made us all some bacon butties for breakfast. Pam was also well prepared at dinner time with a large supply hotdogs which she kindly cooked for us all. A big thankyou to Pam for the effort she puts in keeping us all well-fed in addition to the many other things she does.

 

Boultham park summer fair station

Boultham park summer fair station

 

 

 

 

 

 

With the station up and running it didn’t take long before it was agreed that the new antenna, the Gap Eagle in the images above, was a worth while purchase as we were soon making good distance contacts on HF. A good contact to Bolsover on 2m was also made using Les’s small collinear.

Boultham park summer fair HF Station

Boultham park summer fair station

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

With temperatures rising any piece of shade was a needed place to be with the rear door of Les’s van providing just that.

G4EVK trying to check his camera in the bright sunlight

 

 

 

 

 

 

 

We were also joined by two SWL’s, Lyon and Liz, who are currently studying for the Foundation course. Les, the clubs trainer, took an opportunity during a quite period to start some of the practical’s required for the foundation exam. With the help of Stephen, 2E0SSM, who was out wandering round all the stalls with a handheld, their first supervised 2m QSO was made and signed off.

Liz and Lyon listening and learning with their Baofang’s

 

 

 

 

 

 

 

At about 3pm the show was treated to a flypast by one of the BBMF’s Hurricanes.

 

 

 

 

 

 

By 4pm it was time to get packed up and squeeze things back into the van.

 

 

 

 

 

 

 

Fir Park Wings and Wheels

Reminder to all, LSWC will be out again for the August Bank Holiday 3 Day, 25th – 27th, Fir Park Wings and Wheels event. In the mean time remember the club meets every Wednesday evening and Saturday mornings.

 

So until next time….

Jul 142018
 

Last weekend, 7th-8th July, the club put on a station for VHF National Field Day.

The intention of this weekend was to have a social weekend for all members and to allow those who have not participated in a contest, me being one of them, to try things out in a relaxed and chilled manor.

 

Setting up G5FZ/P

After Preparing equipment on the Wednesday before, Les G1LQB, Stephen 2E0SSM, Alistair M0TEF & Steve M5ZZZ were down early on the Saturday morning to load up the equipment.

 

Les Ready with the Trailer mast

 

 

 

 

 

 

 

Once ready, the team headed up to the old RAF Scampton bomb dump where most of them would be stationed for the remainder of the weekend.

Fitting Antennas to the mast

Fitting Antennas to the mast

Fitting Antennas to the mast

 

 

 

 

 

 

 

On Arrival we were soon joined by Fred G4HNQ & Peter 2E0FGA. The first task was to get the antennas mounted on the mast and the mast winched up into position. One thing that should’ve been done before raising the mast would have been to test the rotator. Unfortunately we all forgot until the station was set up, only to find the controller we brought didn’t work. Fortunately, with the shack only being a few minutes away, Stephen rushed back to search for another one. Returning a few minutes later with a replacement and the station was ready for TX testing. It was found that the log-periodic that was brought gave a high SWR on all bands and it was suspected the Coax to be at fault as it had not been used for a while. The 2/70 beam however worked perfectly.

 

Les Setting up the Camp

Les Setting up the Camp

The Portable station for the weekend

The Portable station for the weekend

The setup Team

The setup team, minus me behind the camera

The Whole Station

Time for Operating

After a few QSO’s were made to test the setup all was ready for the Contest to start.

The contest soon got underway with various people taking the hot seat in front of the radio.

2E0SSM operating the station M0TEF operating the station

 

 

 

 

 

 

 

 

 

As the day progressed the contacts started to come in and as the conditions improved one contact was made with a distance of 700km on 2m. Who says the 2m band is for local contacts only?

Night Shots Night Shots Night Shots Night Shots Night Shots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As the sun set the radio was kept in use until late into the evening. It was at this time that Stephen & Peter had to head home leaving Alistair and Les to man the night shift.

 

After some sleep in cars and tents Pam G4STO stopped by to provide breakfast. before heading off. Switching on the radio Alistair heard a station calling DA0FF. After checking the logging software to find we hadn’t had them before he started calling back. After battling the conditions the QSO was completed at a grand total of 786km. During the morning Fred G4HNQ returned and helped pack away.

Throughout the weekend there was a constant battle against the flies and bugs especially while we packed up on the Sunday.

After getting the equipment back to the shack everyone headed home worn out and sleepy from the enjoyable weekend.

 

The Grand Total at the end of the weekend was:

2m, 62 Contacts with a total of 21,675 points.

70cm, 15 Contacts with a total of 4,408 point.

The log submission deadline is in a few days so we will have to wait and see where we end up in the tables.

 

2m QSO Map

70cm QSO Map

 

 

 

 

 

 

 

With Such a successful weekend the club intends to put on more events like this in the future so keep your eyes pealed.

Feb 172018
 

On Thursday 15th February 2018, club members Roger (G3PVU), Les (G1LQB), Steve (M5ZZZ), Alistair (M0TEF) and Peter (2E0FGA) installed the Hy-Gain TH-5, 5 element, 3 band (10m, 15m and 20m) beam antenna at the Lincoln Shortwave Club site. Pam (G4STO) kindly prepared lunch for the team.

Alistair (M0TEF) reported performance was good with some big signals coming in from the states.

An added bonus was an air display from the Red Arrows, who are based at RAF Scampton. Find out more about the Red arrows here.

G5FZ Hy-Gain TH-5 Antenna

G5FZ Hy-Gain TH-5 Antenna

 

Feb 112018
 

SDRplay RSP2Lincoln Shortwave Club is delighted to announce to members that with agreement from the committee it has just purchased an SDRplay RSP2 SDR receiver for the club shack.

The RSP2 receiver covers 1KHz to 2GHz (VLF > Microwaves> and besides having three software selectable antenna inputs it also has an amazing 10MHz bandwidth.

Using a large number of readily available software applications with the RSP2 makes this an extremely capable general coverage receiver.

The receiver will be installed in the shack in the next couple of weeks and we will organise some training sessions for club members who are not familiar with the hardware & software but wish to experience it.

If you want any more information about the RSP2 from SDRplay please see the link below:

SDRplay RSP2

You may also be interested to know that SDRplay featured in episode 20 of TX Factor. Click here  to watch on YouTube.

Adrian M0NWK
LSWC Committee