PA1B analyses my 137kHz WSPR results

Bert PA1B has done some interesting "reverse analysis" of the WSPR reports I've given people. Working back from these you can estimate the lowest levels (in mW) that they could have used and still been copyable with me. This also gives a good guide to the likelihood of these stations receiving my weak signal. It is clear that M0BMU should be able to copy my 50uW ERP signal frequently (which he does) but that I'd need a lot more ERP to be able to get reports from the PA stations or SM6BHZ. See attached table from Bert.

137kHz transverter update

Breadboarded 137kHz 8W transverter (ERP 50uW from antenna)

Simple 137kHz QRP transverter - click for larger image

Today I combined the RX and TX parts of my 137kHz QRP transverter for the first time and all is working although I'm losing a few dB in RX sensitivity at the moment. Copying DL, SM, PA and G stations on WSPR RX. Best DX being 148km on WSPR TX.  Who says LF has to be hard? HI.

DRM - a waste of money?

Does anyone know how much the cash-strapped BBC is spending on DRM transmissions on shortwave ? Also, does anyone actually use a proper SW receiver equipped to receive this mode? Surely this mode is a total waste of money.

4m transverter paper design

Today I have been gathering data and information for my 4m QRP transverter and started on an "on paper" design around an NE602 RX mixer, 2N3904  3rd overtone oscillator, 2N3904 driver(s) and a 2N3866 PA. It is surprising how much can be done on paper before you start by referring to datasheets and on-line RF calculators. I'm wondering if my T50-6 toroids will just stretch to 4m.

500kHz WSPR - a good evening

A decent set of reports this evening with my 1mW ERP WSPR beacon on 500kHz. Best DX DF4PV's report at 597km. Also I copied Gerhard DI2AF's WSPR beacon (just over 800km) higher up the band on 505.13kHz.

FT817 antenna pin: getting a DC voltage on the inner when on TX.

The FT817 does not have a DC voltage change between RX and TX on the antenna connector, unlike the old IC202. This voltage was very useful to switch PAs and transverters. I now know how to modify the FT817 to add this feature thanks to Chris GM4YLN who sent the link http://www.kolumbus.fi/oh5iy/HW/Yaesu.html showing one way to make the mod.. Note in this link the FT817 is wrongly called the FT718. An easier to implement link is shown at http://www.bergtag.de/download/ft817.pdf . Thanks again to Chris for this one too.

4m Chinese Multimode rig and a FT817 successor from China?

There are rumours, apparently with some substance, that a Chinese mulitmode transceiver for 4m may be being designed. This would not be too surprising, although expect some delay between "being designed" and being available in the shops.

Of course, with several Chinese FM handhelds and mobiles now available at competitive prices from 4m - 70cm it can only be a matter of time before a Chinese equivalent to the FT817's successor (yes we are still waiting, waiting, waiting Yaesu!) will hit the streets, and at a knock-out price. It would not surprise me one bit if such a rig appeared before the end of 2011. Once the Chinese realise they have a ready market for quality ham gear then look out Icom, Yaesu and Kenwood as your days may be numbered, seriously.

Poland soon on 4m

70.1 - 70.3 MHz will soon be available to the Polish radio amateur service on secondary basis. The maximum power will be 20W EIRP. Date of release still not known yet.

4m transverter

It is almost certain now that my next project will be a 5W transverter for 4m. This is a band I have never used under my own call and for which I have no gear yet. The design should be straightforward transverting to 10m with the FT817 as the driver. I have started a 4m QRP transverter page on my website to track progress of this build.

No luck with OE3GHB and G3XIZ on 8.97kHz today

Despite having my antenna and receiver system well optimised and running a Spectrum Lab configuration file allowing very sensitive detection (DFCW6000), nothing (so far) was identified from either Gerhard OE3GHB or Chris G3XIZ on 8.97kHz today. So far, the only station I have "seen" on VLF is DK7FC/P back in December. Since then I've improved the set-up. G3XIZ didn't have his "balloon extended" antenna in place, so he could be several dB stronger the next time he tries again.