AmateurRadio.com

In his review of the Yaesu FTDX5000 in the June 2010 issue of RadCom, Peter Hart G3SJX criticizes Yaesu for not providing a USB interface as Icom does with its IC7600 transceiver. This same criticism is frequently made by new users or prospective users of the Elecraft K3. I think it is an extremely shortsighted view and I’m surprised to hear it from someone of G3SJX’s experience. This seems to be another example of the “it’s newer technology so it must be better” attitude that seems to be taking root in the hobby.

The RS-232 serial port has been around since long before the personal computer. It has not been used for “consumer” equipment since the days when printers and modems came with a serial interface, which is why RS-232 ports are no longer provided with new PCs. But it is nonsense to claim that RS-232 is obsolete because of this. Adding a couple of serial ports to a PC is simply a matter of opening the case and slotting in an RS-232 board. Granted, it isn’t as easy if you are using a laptop, which is why RS-232 to USB adapters exist. But expandable desktop or tower PCs have so many advantages that why anyone would choose to use a laptop for their shack computer beats me.

Icom uses USB not just for computer control but also for audio so the IC7600 doesn’t need the sound card and requires only a single cable to connect it with the PC. This is an innovation that has obvious marketing appeal – which is no doubt why Icom included it. But it’s a benefit that can only be enjoyed by users of specific versions of Windows. If you use Linux, Mac OS, Windows 2000 or earlier or Windows XP 64-bit you’re out of luck. RS-232 on the other hand is supported natively by just about any computer running any OS, by microcontrollers and even by non-computer devices like Ethernet serial port servers. It offers far more choices, even if most of those choices are only of interest to a minority of users.

Buy a device with USB and you are dependent for its continued usability on the willingness of its manufacturer to develop drivers for as yet unreleased operating systems. I’ve had to junk perfectly good printers and scanners in the past because the latest drivers were for Windows 98 or Windows 2000 and the manufacturer did not produce any for Windows XP. Most radios have a life of 20 or 30 years, considerably longer than most computer hardware, so designing into them an interface that itself may have been replaced by something faster and better in the PCs of 10 or 15 years time seems to me very shortsighted.

Icom chose to provide a Windows-only supported USB interface on the IC7600 for purely marketing reasons. Elecraft arguably made the best decision with the K3 by not just providing a true RS-232 interface (not a lame TTL version requiring an extra-cost level converting cable) but also making the DTR and RTS signals optionally usable for PTT control and CW keying. Although separate audio cables and use of a sound card are needed, Elecraft included isolating transformers so no separate interface (RigBlaster etc.) is needed. If Yaesu chose to emulate this aspect of the K3 design as well then it should be commended not criticized.

On my first outing with the Intek H-520 Plus handheld transceiver a week ago I found that the batteries died as soon as I pressed the PTT. It turns out that this is a very common problem with this transceiver. M3XEM has even made a video about it which he has posted on YouTube.

After trying some different NiMH cells, freshly charged, my H-520 seemed to be happy using my longer whip antennas, though it still wouldn’t work with the supplied mini-whip. But after only a little use of the batteries it began cutting out again when using a 2ft centre-loaded whip. The only antenna it would still accept was the 4ft whip with counterpoise. I felt that something wasn’t right, so I decided to investigate.

I measured the battery voltage and current. The batteries were not freshly charged but had been used on Sunday to make numerous calls though no contacts. With the radio turned on and receiving the current drain is 90mA and the battery voltage was 7.71V. This is substantially above the 7.2V nominal voltage which suggests that there should be plenty of life still left in the batteries. This was confirmed by the battery state indicator.

I then transmitted into a dummy load. On the 1W setting (with slightly under 1W output) the current drawn was 750mA. On the 4W setting (with about 3.5W measured output) the current drawn was 1.3A. The voltage across the batteries whilst full power was being transmitted dropped to 6.75V, significantly less than the 7.2V nominal voltage. The current consumption is not excessive in comparison to an FT-817 which is specified to draw up to 2.0A at 5W output. One factor contributing to the voltage drop is the use of separate AA cells. Most handheld radios use battery packs in which the cells are welded together to minimize resistive losses.

The radio still worked fine at 6.75V, but this was transmitting into a dummy load. On most of my 10m antennas – and as observed by M3XEM – the battery voltage would fall away after a couple of seconds and the radio would cut out and restart. I tried to measure the voltage across the batteries when using the two short whips and it fell right away to 3 or 4 volts! This explained why the radio cut out and restarted. It must be drawing a lot of current to cause such a large drop, but I was unable to measure exactly how much as the radio’s voltage sensor cut the power to the TX too quickly for my meter to catch the reading.

My conclusion is that when presented with a load that is something other than 50 ohms, the PA of the H-520 draws an increased current. This effect is significant enough that the radio cuts out even on the 1W setting using the mini-whip antenna. This current draw may be more than rechargeable AA cells are designed to sustain, quickly pulling the voltage below the “low voltage” sensor level.

The transceiver isn’t really “eating the batteries” as some users have claimed, as the cells quickly recover their original voltage when the load is removed. The problem is purely and simply poor design which causes the PA to behave in this way and draw too much current when presented with a mismatch. As can be seen from the schematic (which is included in the manual) there is no SWR protection to back off the power.

It is very unlikely for a whip antenna on a hand held radio to present a perfect match, so the H-520’s performance in this respect is lamentable. As I noted in an earlier post, the supplied whip antenna was found to give its best match at 28.5MHz. It would present a high SWR on the UK and EU CB frequencies that most buyers of this radio would use and I doubt if any buyer of this particular radio would have found it possible to use the highest power setting with this antenna.

Another glorious day and Olga and I took a picnic lunch up to Watch Hill. We go there not because it is a SOTA summit but because it is near home, a nice walk, not a steep climb (so Olga is happy to come with me) and one of the easiest operating sites for me to reach when I want to get away from all the electronic QRN I’m plagued with at home. Unfortunately there isn’t a picnic table up there and I haven’t yet found a way to support the MP-1 antenna on a bare hilltop. Using a right-angled PL-259 adapter and a 259 to 3/8 adapter on the back of the FT-817 only works if you have a level surface to put the radio on and no breeze. So despite taking them with me I wasn’t able to get any use out of them. No doubt a photo tripod would do the job but that is too much ironmongery for me.

I did also take the Intek H-520 Plus and a couple of BNC mounted whip antennas but although there clearly was propagation on 10m I didn’t manage to work anything. I did hear something puzzling though. After one call on 29.600 I heard what I’m sure was a native English speaking voice announced something on the lines that this was the EA????? repeater. Unfortunately I’m getting increasingly slow witted these days so I don’t remember the exact announcement nor the full call and I didn’t hear it again. 29.600 is supposed to be the 10m FM calling frequency and not a repeater output so what could it possibly have been?

Back home later in the afternoon and VHFDX.net showed that there was a big Sporadic-E opening on 6m and even 2m in Eastern Europe. I decided to try 10m which seems to be the neglected band and managed to make several contacts including a new country for me, OD5NH in Beirut, Lebanon.

The Beach Boys Amateur Radio Club went to work on Saturday morning and rested five hours later after prepping antenna systems. I was tired and a few aches reminded me that taking care of myself is really important. Our team enjoyed its morning and afternoon beneath the solar disc with the blue Pacific over our shoulders. The day was ideal for tackling Field Day logistics and preparation.

We are passionately committed to our project goals such as ham radio fun, operating outdoors, learning, and deploying a competitive signal from our location. The Beach Boys Amateur Radio Club is an informal group letting our enthusiasm for the hobby drive our organizational goals.

Tower.
Our antenna systems arrived to include a 30 foot tower, a tri-bander, a vertical, a VHF quad, and a flat top dipole. The biggest challenge inside the project is the tower. We brainstormed safety principles and focused on the tower base plate. It required 3 foot steel stakes with clips and washers. The team concurred that a stake system in addition to proper guying will maximize our safety.

Our next goal is a practice run at deploying and guying the tower with the tri-bander attached to the rotor mast while keeping safety in mind at all times. Additionally, keeping the rules out in front of us, the entire system is dissembled prior to Field Day operation.

Flat Top Dipole.
Ham radio fun picked up momentum after a pair of operators slung rope into a pair of trees for the flat top dipole. Theoretically, launching rope into tree branches as easy on paper as it seems, is not a straight forward process. It was work and required a few attempts before achieving success. The moment was sweet when we fired up a TS440S on 40m lower sideband and logged a Nevada along with a California station.

The buzz around the work party, “What was the signal report?”

Vertical.
Another team of operators deployed our vertical antenna system for operational testing on the low bands. It’s intentionally positioned at the furthest end of our site to thwart cross band interference. There is nothing more discouraging when stations begin interfering with each other. It is the fast track to frustration.

Counterpoise is everything for a vertical. Pundits may say otherwise, however, I advocate wire beneath one’s vertical. We have the benefit of a large metal-like cage near the feed point surrounding this antenna as an added bonus. The antenna analyzer data suggested reasonable standing wave ratio although I’m learning how-to calculate efficiency.

Additionally, we will deploy a rudiment counterpoise system of quarter wavelength radials or near quarter wavelength given our on-going debate. This system will be above ground but not equal to the height of the feed point.

Conclusion.
The Beach Boys Amateur Radio Club party benefited all those in attendance. We tested two out of three antenna systems, assembled the tower with rotor, improved base plate security, and ended the day exhausted. Everyone enjoyed working outdoors, getting their hands dirty, and learning about antennas in preparation for this year’s Field Day.

73 from the shack relaxation zone.

Once again, WSPR is revealing the existence of consistent propagation paths every day on 10m between Iceland (TF), the Faroes (OY) and northern Norway (LA/LB) and the UK and north-west Europe when there is no Sporadic-E and no other propagation except over very short distances between closely located stations. This has occurred even during periods of zero sunspots.

I’m guessing that because we have only in the last few weeks had a large number of WSPR monitors on 10m because of the Sporadic-E season, no-one has previously observed it. But I’m surprised at the lack of comment about it. Perhaps this is a phenomena known to everyone but me, in which case I’d welcome some enlightenment.

From John Harper AE5X’s blog I have discovered that Ten Tec will be re-branding the Chinese HB-1A QRP CW transceiver. The Ten Tec versions aren’t exactly the same – they will be selling two versions, one covering 40 and 30 metres and one covering 30 and 20 metres whereas the original covers 40, 30 and 20. This may have something to do with meeting FCC spurious emissions specifications.

As it happens, my HB-1A is on eBay at this very moment. Not that there is anything wrong with it, just that it doesn’t do anything that my FT-817 can’t do and I’ve spent quite a lot on new radios recently so it seems right to dispose of some of the ones that aren’t being used.

But its performance wasn’t exactly spectacular. It’s a bit sad to see the company that made and discontinued the Argonaut 516 HF QRP rig and matching 526 6’n’2 metre rig offering such a basic radio as its only QRP product.

I’d love a Ten Tec 516 / 526 pair, so if anyone has one in mint condition that they’d like to sell or trade for an Elecraft K3/100 drop me an email.