Waters and Stanton - wake up guys!

Today, having still received no feedback from Waters and Stanton about my emailed question on the FT-450D TX hum (has Yaesu fixed it yet?), I decided to ring them up, check prices and ask the question directly. To my amazement the sales person said, "I have never heard of the TX hum problem". Well, he can't be too well in touch with the market and customers then.

I also asked what was the best price for the rig ("same as in the magazines, no deals") and then asked if they still had the 3 year warranty running. "What 3 year warranty? I've never heard of that." I pointed him in the direction of several recent RadCom and Practical Wireless adverts.

In summary, I was NOT impressed with the responses, or rather lack of them, from this well known UK supplier. At a time when business near Christmas is tight surely it is important that sales staff  know about the product and can answer questions as simple as "what is the length of the warranty?".

Unless this supplier wakes up a bit I think I will defer my decision about purchasing the FT-450D.

Incidentally, they did say that Yaesu would be at Hockley this weekend for the W&S open day. I expect people going will ask about the TX hum question directly. And I wonder if there will be any news about the FT817's replacement?

Simple speech processing

Recently Peter Thornton G6NGR sent me a number of example circuits for speech processors, some dating back to the 1960s. Anyone who operates QRP SSB on HF or VHF will appreciate how important "punchy audio" is when running low power. One circuit I remember working extremely well was one based on an idea by John Hay G3TDZ. Back in the 1970s I was using 100mW AM on 2m and wanted to be heard across Cambridgeshire. My audio stage consisted of a couple of pre-emphasis stages followed by a hard audio clipper and a low pass active filter. The result was an amazingly punchy signal with barely any change in audio level when talking. The 12dB/octave pre-emphasis helped to ensure that clipping of LF signals did not result in many artifacts within the audio passband. The LPF was essential because the heavy clipping  results in many audio harmonics which would otherwise result in a broadened signal. With just 100mW and a dipole the QRP AM signal was excellent copy across the county. I keep meaning to try the same circuit (if I can remember it) with the FT817. It would produce a mighty punchy QRP signal!

KX3 release date

The Elecraft KX3 10W QRP transceiver is edging slowly towards formal release for orders. There is an enormous pent up demand for this 0.1- 10W QRP full featured HF/6m radio. Elecraft are still expecting to be able to announce that orders can be placed by the end of December with first products reaching customers in Feb 2012. I am still unsure if this is a possible candidate for my replacement to the IC703.

FT-450D hum?

Although usually/mostly a QRP operator, I've been considering an update to my main station transceiver since selling my 10W IC703 to a local friend. One possible candidate rig is the 5-100W Yaesu FT-450D. It is getting very good reviews with excellent comments on its  receiver features. For a "full feature" HF/6m radio it is good value for money.

But, I am bothered about one thing: many reviews and comments on the FT-450D Yahoo group confirm a design issue with TX hum, believed to eminate from the poor grounding of the display unit. Nothing I've seen or heard has convinced me this widely reported issue has yet been properly fixed by Yaesu. This is not a problem with the display set to its brightest setting, but should one pay around £800 for a radio with a fundamental design issue not solved in a recent upgrade? No.  A question to Waters and Stanton asking if Yaesu has fixed it has not received a reply yet after 2 days: I suspect they don't want to say "no". I have said that if it hums it would be returned.  So, until I hear the problem has been resolved my "buy" decision is on hold. I am in no great hurry.

More optical comms tests

A few days ago I received some 10000mcd 5mm "high brightness" Toshiba TLSH180P LEDs from Maplins.  Today I did some tests without optics using these. Still using just my NE555 1kHz oscillator output directly driving the LED the signal is considerably brighter. It should be some 10dB better than the high brightness LED used before. Using the Toshiba LED both as TX and (unbiased) RX detector the signal could be detected over a range of around 20m in daylight. The beamwidth of the LEDs is narrower (8 degrees) so aiming is quite critical. Further may well be possible with very careful beam alignment.

So, with 100mm lenses at each end (24dB minimum gain each) 5km should be possible and maybe up to 20km.  Progress on the full FM/SSB systems has slowed as Christmas approaches with other activities taking priorities in the family, but the 481THz work is my main priority ham radio-wise.

You Kits SSB transceivers

For some reason I have missed the news that YouKits are producing (or about to) 2 band and 4 band HF SSB/CW transceiver kits at very reasonable prices. See http://www.youkits.com/ . One is a backpack and one a handheld. Quite interesting. See TJ2A and TJ4A code numbers on their website.

Micropower generation/power harvesting

Linear Technology lists the LTC3108, an Ultralow Voltage Step-Up Converter and Power Manager than runs with an input of just 20mV producing a 5V output to power things such as low power wireless devices and processors. Surely there must be an application for such a device in ultra-QRP portable equipment? Imagine, where can you find 20-500mV of noise from? 50Hz crud in the ground, a thermo electric sensor, solar cells etc. I wonder who will be the first person to make a QRPp uW beacon powered using the 50/60Hz buzz available between a couple of earth electrodes in the ground?

Elecraft KX3 internal photos

Elecraft KX3 rear view inside

Lots of QRP operators are eagerly awaiting the release of the KX3 from Elecraft early in 2012. This is a very compact all mode 10W rig suitable for home or field use. It was first lauched back in May 2011 and Elecraft have been busy completing the design and doing field tests. I came across some internal photos on VA3KV's site that I'd not seen before which give some idea of the design. It can be fitted with internal batteries and an internal wide range auto-ATU making it a very versatile transceiver packed with features. Spec is expected to be excellent and not far off that of the K3.

481THz progress update

TX beacon optics

This morning I bought a length of 110mm waste pipe from the local Plumb Centre shop. It came in a 3m length and only just fitted in the car to get it home! After lunch I created my first attempt at some optics inserting my Poundland 100mm lens into the end of a cut section of the pipe. At the focal length I mounted my 10 pence high brightness, prefocussed, LED beacon with Bluetac. With this (crude) set-up on an old tripod and with a taped on gun-sight to help with aim, I set the TX baseband beacon running and pointed it from the stairway through a double glazed window aiming down the road. With my handheld baseband head using just the high brightness 10p LED as the detector I walked down the road to see how far I could get. In the beam in daylight I could detect the signal at the receiver at 120m. With a magnifying glass in front of the RX LED signals at 200m were strong (could not test at greater range), but it was difficult to keep the RX aligned. The red LED was quite strong visibly at the 200m test point even though running just 15mA or so through it. The double glazed window no doubt added a small amount of attenuation. What I'm not sure about is how good (or bad) this result is. Clearly with a really high brightness Golden Dragon LED the range even with this system would be considerably further.

LF tests with the earth electrode "antenna"

Following the great success on 160m with the 20m spaced earth electrodes yesterday, I fired up the WSPR transverter into the same "antenna" today on 137.5kHz. Although I managed to decode G8IMR at 188km several times, no reports of my signal were received. This ties up with tests last year which suggested the earth electrode system was around 8dB down on my 80sq m vertical wire loop. With results on 137.5kHz hard to get with 500uW ERP it was perhaps not surprising that no-one managed to decode me on the earth electrodes.

I now have a choice on 137kHz: either re-erect the wire loop, but double the wire thickness when I do so, or change to a Marconi vertical with a large loading coil. The thicker loop will increase ERP by up to 6dB but I suspect more is to be had with the vertical. It would be daft of me not to give the Marconi a try both on 137.5kHz and on 500kHz. Even with my limited space I can still manage around 8m of vertical with around 20m of top section.