The LSWC 2018 Construction Contest

 Arduino, Contests, Home Brew  No Responses »
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.

FirPark Wings & Wheels

 Special Event Station  No Responses »
Sep 032018
 

LSWC was once again at the FirPark Wings & Wheels event. The Club was there from Friday afternoon through to Monday evening of the August Bank holiday weekend.

 

Friday

Friday afternoon Les G1LQB, Peter 2E0FGA, Stephen 2E0SSM, Steve M5ZZZ set off for FirPark from their various starting locations. Les arrived first and started setting up and putting the masts up, the great thing about the masts we use are that they are designed to be erected by one person.

In addition to previous years Steve brought down his 2m / 70cm beam and along with Les’s special rotator, aquired at a previous FirPark event, we had 2m / 70cm SSB available using the icom ic-910. We also had the usual fan dipoles covering all of the HF bands and Les’s X30 collinear for 2m / 70cm FM.

 

By Night fall on the Friday the antennas were ready to lifted into position in the morning for operation to begin.

 

Saturday

Saturday morning saw the antennas raised into position and operating began.

Image thanks to Les G1LQB

Image thanks to Les G1LQB

LSWC portable at FirPark Wings & Wheels

 

 

 

 

 

 

 

 

 

 

 

 

 

Some contacts were made using various modes, Including CW, FM, Via Satellites and SSB on HF and 2m. One of which being an SSB contact to America. We were also joined by Mick, M6OYP and his dog for the morning.

 

2E0SSM working satellites. Image thanks to Les G1LQB

2E0SSM working satellites. Image thanks to Les G1LQB

 

 

 

 

 

 

 

 

Pam G4STO also joined us and brought with her the usual sausages and burgers, although an unfortunate dog incident occurred with the burgers, and cooked us a late breakfast and then some lunch. We were also joined by Barry G4DBS who spent some time on the radio.

 

During the day we had a number of people come and speak to us with a couple taking away Foundation books and some magazines. We hope we will hear from them again to do there Foundation licence.

As the day come to an end Les, Stephen and Peter were left to camp over and were treated to a nice sunset.

Sunset at FirPark Wings & Wheels Sunset at FirPark Wings & Wheels

 

 

 

 

 

 

 

Sunday

After a chilly night the three campers arose on Sunday morning ready for another day.

 

Sunday we were joined by Tom G4OSB, who took up the key on HF making a few contacts in the morning. By 11am though the weather had turned and the rain began to fall. The public had left and some stall holders had packed up and headed for somewhere warmer. Les, Stephen, Peter, Steve and Tom braved the weather before Tom and Peter had to depart leaving just three to continue. Band conditions started to improve with some good contacts made two of which to other special even stations in other parts of Europe.

 

Monday

Soon Monday arrived and reading a post on the internet Stephen read that the digipeater on the ISS was surprisingly back up and running. So to see if this was true he got out his Tape measure Yagi and hooked it up to his handheld radio. Using the built in TNC / APRS he transmitted the packets not expecting to get a reply.

 

2E0SSM working the ISS with APPRS. Images thanks to Les G1LQB

2E0SSM working the ISS with APPRS. Images thanks to Les G1LQB

2E0SSM working the ISS with APPRS. Images thanks to Les G1LQB

2E0SSM working the ISS with APPRS. Images thanks to Les G1LQB

 

 

 

 

 

 

 

 

After just his second transmission he got a reply back acknowledging his message and once the pass had finished he checked the received calls log on the internet and was delighted to see his callsign listed.

 

As the day went on we were joined for a brief period by Roger G3PVU & Jackie. Conditions on the bands were still quiet with mainly UK stations on 80m with one or two further afield on 40m. With the weather being better the other stall holders returned and so did the public. More people come to ask questions and see what was involved. As the winds picked up it was soon just Stephen, Les and Steve remaining but when Steve had to head off for other reasons Les and Stephen decided it was time to pack up and head home.

 

Next Time

The LSWC will be back at FirPark with some potential improvements to the station there being worked on next year.

Boultham Park Summer Fair 2018

 Portable  No Responses »
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….

Hy-Gain TH5 Antenna Installation

 Antennas, LSWC Shack  No Responses »
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

 

SDRplay RSP2

 LSWC Shack  No Responses »
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