FT-450D hum: a good response from Yaesu

Last night I wrote to Yaesu UK about the FT-450D hum issue and got a very fast and very helpful, response from Paul Bigwood their Technical Sales Manager. All credit to him.

I will paraphrase Paul's reply below.

He confirms the hum problem has been recognised and that it doesn't affect all radios. Those it does, are only affected in voice modes, when the display brightness is reduced below its normal maximum level. The level of hum is generally low and is usually only noticeable when the received signal strength is high [i.e. with local stations], DX stations don't normally hear it.  He says that steps have been taken to resolve the issue and product shipping into the UK dealers since the beginning of the year have a modification to resolve it. He told me that if I purchased one that does suffer from hum under the circumstances as above, then it can be returned to Yaesu for updating under warranty.

He went on to say,

"Please rest assured that Yaesu does care about its products, their reliability and performance. We certainly look to resolve any problems as soon as they become known to us.  The FT450D is a splendid radio, having done excellently at the T32C DXpedition last year when over 200K QSOs were made with no reports to us of any hum problems."

I thought this was an excellent and totally professional response. Yaesu is a first class manufacturer and it is reassuring to see they have taken on board the hum issue in this otherwise excellent little radio and have now taken steps to properly fix it on new build units.

137kHz transverter bites the dust

Having re-erected my 80m loop antenna I was about to reload OPERA and give it a try now it appears more stable. I ran up the transverter on WSPR to check all was well only to have the power supply suddenly take around 20A and shut itself down.  I think the MOSFET PA died on me. All being well I will get this fixed next week when my grandson goes back home again and have another try.

Netbooks

For many years I used a little Asus EEE PC701 (7 inch screen) netbook running a pre-loaded Linux OS. This was ideal for basic net surfing and emails, but it lacked the flexibility of a Windows OS when looking for ham radio software. At the moment I am looking at a possible replacement that I can use for general web browsing and also to run WSPR, OPERA and hopefully Spectran and Spectrum Lab freeing up the main PC. Such a small netbook would also be useful for field use with VLF tests, lightbeam experiments etc.

It is quite amazing what £200-250 will buy today. My first laptop cost me £1499 back in 1998 and the performance was nowhere near that of even my little Asus EE PC701!

My inclination is to buy another Asus machine unless someone can give me good reasons to choose another make.

A new meteor scatter mode

http://www.dk5ew.de/2012/01/13/psk2k-a-new-meteorscatter-mode-by-dj5hg/

This webpage gives details of an interesting high speed MS mode from DK5EW. There is also a Yahoo group to discuss this: see http://uk.groups.yahoo.com/group/psk2k/

"PSK2k is high speed meteor scatter software written by Klaus DJ5HG (Prof. of Computer Science at University Hamburg).  It allows 2 way MS QSO’s to be conducted with any suitable transceiver/PC/soundcard combination.

PSK2k is fully error correcting and call specific in operation so you will only see the QSO in progress and any non-QSO CQ or QST text. All other transmissions (other people also in QSO) are discarded. This allows multiple QSO’s to take place on a single frequency.

PSK2k can be operated in fully automatic mode if required. This enables QSO’s to be completed fully automatically without user intervention. Important advantages are that long term testing can be done, on QRP power for instance, without having to sit an monitor every period."

Philips FM321 70cm mobile

The very first FM synthesised 70cm rig in the UK was made by Philips in Australia and was called the FM321. This 4W mobile was based on the very similar FM320 designed for the Australian UHF CB band. I owned an FM321 for a couple of years back in the early 1980s and really enjoyed using it on the UHF simplex channels and repeaters. Ergonomically it was excellent with simple up-down channel change and a decent volume control. It is a pity rigs are not made as simple as this today. No memories, no fuss.

From the home QTH and with just a hand rotated small vertical yagi I could work some impressive DX on FM on some days. That's the thing about 70cms: propagation changes within hours and often in very localised directions. When there was plenty of simplex activity it was very interesting watching propagation change and the maximum range change from maybe 30 miles to over 100.

WRC-12 Radio Conference (Jan 23 - Feb 17)

This most important international frequency revision conference takes place Jan 23th - Feb 17th. As always, the amateur service can never be certain of the outcome with a possibility of precious spectrum being lost to other services. However, this time there is a good chance that we will GAIN a new amateur MF band somewhere between  415 and 526.5kHz. The most likely outcome is a band near 480kHz around 8kHz wide. 8kHz of spectrum would allow much more experimentation, especially if this allocation was world-wide. This would supersede the special permits around 500kHz allocated in some countries.

Nice antenna for 80m QRP?

This is most definitely NOT my idea of amateur radio, but you can't fail to be impressed at the dedication of this Russian amateur to put out a big signal on 3.5MHz. This is a full sized 3 element yagi for 80m, meaning the driven element must be about 40m long.

Optical RX improvements

G8CYW Optical head (April 2011 RadCom)

I've now bought some NE5534 low noise op-amps so can implement the full G8CYW optical head circuit which many users have successfully adopted. Stuart describes this as "exquisitely sensitive". I have BPW34 PIN diodes but think the sensitivity should be similar to that with the SFH2030 diodes used in Stuart's design.

In the first instance I need to remeasure the noise floor with the optical head in total darkness to see if the changes indeed make it better than the current discrete component circuit.  My first quantitative noise measurements suggest far higher noise floor than I expected.

Assuming this gives improved performance over my 0.4km local "up the road" test range, my next step is to attempt a longer path, so I am looking for a path of around 2-3km to test with my baseband beacon. If this works with decent S/N then I'll retry looking for the GB3CAM optical beacon. At 32km this is a good test of system performance. At the test site at Nine Mile Hill the traffic noise was high (optically and audibly) so I also need to increase the signal level in the earpiece used to align the RX.

There is also soon to be a second optical beacon near Cambridge and this should be a little closer and an easier signal to find. However, I need to do tests before this is installed at Dry Drayton.

Incidentally, I managed to overcome the parallax issue in the optics alignment  so now a distant street light is spot on in the cross-hairs of the spotting scope.

FT-450D Hum (again)

From what I see and hear, Yaesu is still selling this otherwise excellent HF/6m transceiver with a fundamental design flaw: hum created by poor grounding of the display module when dimmed from maximum brightness. This problem was there on the FT450 but whatever improvement, if any, was implemented in the upgrade to the D version,  it has not worked consistently.  This really annoys me: surely this sort of issue should have been picked up in beta testing? The fix being implemented by many owners seems simple, so why the heck doesn't Yaesu get on a fix it?

OPERA (weak signal mode) - a word of warning

Since installing Opera V1.0.4 a few days ago my Inspiron 630m Win XP PC has started to behave very oddly. For years it has worked in a very stable fashion with very few issues in 6 years of use.  Now it is slow (very slow) even when not using OPERA, CPU load is high and running Ccleaner, which usually takes a minute, took nearly AN HOUR to get rid of 156M of files to be cleaned up.  Now, I cannot PROVE the link, but the coincidence is remarkable.

To make matters worse, the software once installed does not appear to be listed in the list to uninstall. Not being a PC expert I am loath to just remove all the obvious files in case this damn program has left something behind that "leaves its mark".

The lesson is DO NOT INSTALL DODGY, UNSTABLE AND POORLY WRITTEN SOFTWARE unless you know what you are doing and you know how to get rid of it safely and completely.

OPERA, as a weak signal mode is interesting, but I am VERY unhappy that it has messed up my good old faithful PC.