Dave Richards AA7EE

March 15, 2011

Keeping Frequencies Clear On HF and The Latest On The CC-40

The news from Japan continues to unfold on a daily basis. After reading so many reports from official news channels and reactions in so many personal blogs, it’s hard to know what to say without repeating what others have said. It is difficult to imagine what those affected must be going through right now.  I don’t imagine it’s possible to know what it’s like to have to go from having a house and a decent life to spending nights in near freezing weather with little or no water, food or other possessions.  One lady who spoke to a reporter was even having to borrow a pair of socks from a neighbor. Imagine losing everything; I don’t think we can unless we were to go through that experience.

JARL has requested that amateurs worldwide keep a set of frequencies clear in order to aid emergency communications efforts by amateurs in Japan. Other reports have requested that we keep clear a window of ±5KHz around these spot frequencies and this seems reasonable, given that Japanese amateurs will be using SSB.  Most of the time it’s pretty unlikely that CW QRP signals from US amateurs will interfere with these emergency communications from Japanese hams, but given the magnitude of this disaster and the fact that theirs is definitely the greater need, I’m keeping clear of 7025-7035 when on 40M, the band on which I spend most of my time, and I hope that others will do so too.

Listening to 7030, it’s apparent that not everyone is doing this. Perhaps they’re not too well connected with the internet and didn’t hear about the request from JARL or perhaps they assume that at many times of day, the chances of them interfering with communications in Japan are slight to nil. The interference justification is a valid one during the daytime but I’m staying away from that window anyway just to be sure, and as a measure of respect. Who knew I would miss a 10KHZ slice of band so much – I hadn’t really thought about it, but on looking through the log, the majority of my QSO’s are on or near 7030. Sure, I go up and down the band, and also to other bands, but for me, the meat and potatoes of my QRP CW life is hanging around 7030.

In the past when looking at designs of simple rockbound transceivers, I often felt that I was giving up a lot by opting for the simplicity of rock-bound design and would direct my interest toward more frequency agile circuits.  In the past year since going almost completely 100% CW with VFO-controlled rigs, when on 40M, I leave the rig on 7030 and sit there. I might as well have opted for the crystal-controlled designs!

The point that I’m trying to get to is that I often mentally discount simpler designs because I want a radio that will “do it all”, or at least do quite a lot.  There are two ways of doing a lot though.  You can either do it on all frequencies, modes and bands, or you can pick one simple approach (in this case QRP CW on 7030) and stick with it. For others, their one thing is CW on Top Band, or eme using JT-65.

Talking of 40M CW, Jason NT7S has experienced a few unforeseen challenges with the design of the CC-40 which have all been overcome. The most recent difficulty resulted in him implementing a design change that actually improves the rig’s performance; current consumption was creeping up towards 40mA on receive but is now in the region of 25mA with no loss in performance, due to cleverly switching off the micro-controller when not in use.  I find the prospect of a 40M superhet with a 500Hz filter that only consumes 25mA quite exciting – especially as I plan to power my station from solar eventually. The frequency coverage will be somewhere in the region of 40-50KHz, so I plan on setting it up to cover the bottom 45KHz or so of the band.  If you told me that I could only have a 50KHz slice of amateur spectrum, I’d opt for 7000-7050 without even stopping to think about it twice, so the CC-40 could well represent my ideal basic amateur rig.

Keeping my fingers crossed, I should to be able to report within a week or two on this blog that the CC-40 Beta Kit has been received at AA7EE, and at that point hopefully Jason will be able to take a brief and much deserved break (I bet he’s laughing as he reads this.)

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