Sunday, 15 May 2016

A bit more 13cm EME and Upcoming Dayton visit

I set up again today to check out some changes I had made in the shack. I've repaired my MFJ memory keyer and can now run either a keyboard or straight key. I may buy a decent paddle at Dayton. My 'peers' keep telling me I need to use CW more if I want to get my speed back up!
Anyway, whilst testing I noticed that although the moon is currently at apogee and therefore the degradation is high, I could occasionally hear as well as see my own echoes with the 200W PA in the shack and with an unacceptable amount of transmit cable loss. My plan is to move the PA out to the dish. The 27V PSU is already out there in a weatherproof case with 110V AC supply and all ready to go.

I am off to Dayton on Thursday and back early the following week. Whilst in Dayton I will be attending the new VHF/UHF weak signal dinner in Miamisburg, Dayton on Friday evening. This new event replaces the excellent event previously run by Tony Emmanuel, WA8RJF, but sadly no longer organised by him.

I will be in the Dayton fleamarket much of the time, on stands 2766-2769 with WA5VJB.
It looks like it will rain (nothing new there, then!) Friday afternoon through Saturday, so I'll need to take the wayerproofs!
I'll report back on Dayton on my return.


Friday, 13 May 2016

2320MHz EME

Today I replaced the 6cm EME feed with the 13cm feed and hooked up the transverter and PA in the shack.
It is no where as critical to track the small 2.3m dish on the lower band as the beamwidth is so much greater.
Although I didn't see any trace of a JT65C signal from D44TVD I was asked on the HB9Q logger by UA3PTW for a sked. His -15dB signal was easy to find and he gve me -16dB. When we had completed I was called by an enormous signal that turned out to be HB9Q. His -11dB was one of the largest signals I have seen on 13cm EME. He gave me -13dB. IK3COJ then askd for a sked and we swapped -15/-20dB
This has brought me up to a logged 21DXCC on the band with 18 of these on EME. I know I have worked many more terrestrial DXCC than the 3 it looks like but these have not been transferred from my paper logs yet.

Thursday, 12 May 2016

5760 EME

I have set up the 6cm EME system to try with the D44TVD dxpedition. He is trying to be QRV at 14:00Z today.
6cm is not my best band due to low transmit power (25W) but sun noise is good and I can see moon noise. JT Echo mode is showing lots of libration and a very weak return. Degradation is high at present.
I may have to change bands to try with him on another day. His 1m dish will make it difficult on any band when I only have the 2.3m dish at this end. But hey, don't try, don't know if it will work!

Friday, 22 April 2016

A little news

I volunteered to act as Chairman of the UK Microwave Group, following the Martlesham Microwave Round Table AGM. I've just heard from one of the current Committee members that my offer has been accepted
No one on the Committee wanted the role, which to be honest can be a bit stressful at times, so I made the offer to act as Chairman for the next year, at which time a prospective, new, Chairman may be willing to take over. 
I have previously been Chairman, taking that role for the first 3 years of the then new UK Microwave Group. 
As one of the original 'Gang of Three' who set up the group when it appeared that the RSGB spectrum committees were probably going to be disbanded, I was extremely pleased to be appointed as the first Chairman and saw the Group through the first, sometimes difficult, few years of its life.
The UKMicrowave Group quickly became the recognised elected voice of UK microwavers. That is a role it has performed well for nearly 17 years. 
OFCOM recognises the Group and has been known to seek our help in matters relating to amateur microwave operation, allocations and even technical help. 
I am pleased my offer to act as Chairman for the year has been accepted and I will do my best to live up to the role.

Sunday, 10 April 2016

Mast maintenance

With the help of G8BHC (Scatterpoint editor) I did some maintenance on my antennas this afternoon. My intention was to replace my failed (coax relay) 2m masthead preamp with a DG8 premp and return to single cable working ( leaving a free coax for 6/4m).
In the event we ended up removing one of my two 23cm 44 element yagis and moving the 67element 13cm yagi into the space vacated. The 3cm dish was moved up the mast (slightly). All of this in addition to fitting the DG8. However, we ran out of time before I could run in the new length of LMR600   coax between the preamp and the shack. I did manage to measure out the run and the new coax was was just long enough.
Listening on 23cm, using the single antenna, didn't reveal any great loss of system performance but time will tell. I have been suspicious of the 23cm antenna combiner and the removal of one antenna seems not to have resulted in a 2-3dB drop in performance, as best I can tell. Similarly the 3cm system was checked out and reception of GB3SEE at -13dB on JT4G was a bit above normal, but probably due more to conditions than the marginal move of the dish to its 'higher' location on the stub mast.
All in all a useful afternoon!

Saturday, 19 March 2016

Anglian transverter

Some of the readers of my blog will be familiar with my Anglian 144MHz transverter kit.
Around 200 of these have been sold with the majority being of the form of an assembled SMD PCB. The builder is then left to install the board in the supplied case, solder in the leaded tunable inductors and the crystal. 
This has worked well and although there has been the occasional dry joint problem, most seem to work first time and provide the builder with a transverter that is high in performance and low in cost whilst allowing the builder to boast that they built it themselves.
I am now coming to the end of the current batch of assembled boards, helped by a recent 'sale'. This has been more successful than expected and the boards have quickly depleted.
My dilemma is what to do next. Having boards assembled has not been without its problems and is by no means an economical way to go with relatively small production runs.
I am not inclined to have any further boards made this way.
Unfortunately the PCBs are designed for reflow solding and therefore have small SMD pads. These are awkward to solder to when using hand soldering.
As the Anglian has been so successful I am reluctant to stop production. Maybe the best way forward is to re-design the board, changing a few aspects of the circuit for even better performance and selling this as a kit where the builder has to solder around 120 SMD and leaded parts onto the board?
With about 12 boards left I am going to have to decide soon!
73 de Sam

Life on 23cm EME

Last weekend I got the 23cm EME system back on line. A careful check of my log shows I had worked 62 'initials' ( first contact with a new station or #) up to May 2012, when I last operated on 2cm EME.
Since last weekend I have brought the initial score up to 74
It is quite clear that a lot of new stations have appeared in the last few years. I recognise a lot of the callsigns as those belonging to customers who have bought an VLNA23 from me. I find that very gratifying!  I think it should be possible to raise the number of # to 100 by the end of the year. At least it gives me a target to aim for and means I will have to keep the 23cm preamp and feed on the dish.
The majority of new contacts have been worked on JT65C and running MAP65 has allowed me to see who is on without sitting in front of the PC laptop all the time.
I can see that not withstanding last weekend's 23cm DUBUS CW EME contest, when up to 16 stations at a time were visible on the spectrum display ( P3 and SVGA card to 23 inch monitor), the move to digital on the band is seriously underway. I realise this will unsettle a good few of the old CW stalwarts, but King Catute showed the fallacy of trying to hold back 'nature'. In this case human nature.
I'm not a good CW operator and am always relieved when a CW contact has finished and in the log, wheras I actually enjoy the surety of digital contacts. It's not fashionable to say this, but I still can't see the attraction of CW when digital allows so much greater reliability of contact exchange information. And for me personally, far less anguish about not copying callsigns correctly or dealing with 'off sequence' information.
Sorry guys!