AmateurRadio.com

Icom Inc. has published firmware update E3 for the IC-7100 on their global website. This new firmware has been designed to improve RX audio quality.

The following firmware have been updated:

• CPU M to Version 1.04
• DSP I to Version 1.02

The new firmware can be downloaded here.

This article follows up on this one. The title could also be: doing measurements on hand held radios is hard. Actually, some measurements I did in the past might not be so accurate after all.

Measuring in dBm
If you measure in dBm, what I always did, you assume that the device at the other end is 50 Ohms, just like the manufacturer promises you in the specs. Slowly but surely we are finding out that this is not always the case. As a result I might have to switch to microvolt (µV), a method which doesn’t require a perfect 50 Ohms at the other end.

Can’t we just convert it? 0.5 µV @ 50 ohms = -113 dBm, a piece of cake, right? No. You must know the actual impedance of the receiver if you want to convert from dBm to µV. Erik PE1RQF did some measurements on a few hand held radios to find out the true impedance. The outcome was, well, a bit scary.

If a device is 50 Ohms, the SWR should be 1:1. Only a perfect dummy load and the Marconi RF generator are.

What this means for us
What this outcome basically means is that generating cold numbers on sensitivity and antenna performance are nice, but don’t tell the whole story, or could be misleading.

• Antennas which prove to be the best performers (RX/TX, VSWR), tested under optimal conditions, are not necessarily the best performers on a specific brand/model of hand held radio.
• There are antennas which aren’t 50 Ohms at all, but could very well outperform everything else on the market because your radio isn’t 50 Ohms either.

Do the test yourself
The best example I can give you is this one: take a Baofeng BF-666S, 777S or 888S, use the stock antenna, and make notes of the performance in the field. Try to hit repeaters which are barely in range. If you have a field strength meter, measure field strength when transmitting.

Remove the stock antenna and replace it by a Nagoya NA-701, NA-771, the $3.79 antenna, or the Baofeng UV-B5 antenna. I tried all of these; just pick whatever 3rd party antenna you have. Repeat the tests.

What happened here is that the short stock antenna was the best of the bunch, all 3rd party antennas had a negative influence on the performance of this specific Baofeng model. The same 3rd party antennas mentioned above did improve the performance of the Baofeng UV-5R, often by a wide margin.

Exception to the rules
The funny thing is that reception suffered greatly too. This is quite uncommon and a sign that hand held radios don’t follow the rules. For example, if you just want to receive on 20 meters and your dipole is 2×6 meters instead of 2×5 meters, you would never notice the difference. With your hand held radio however you will.

Courtesy hamnieuws.nl

Privacy and freedom are constantly traded in for a (often false) sense of security. This has nothing to do with ham radio, you’d probably think, but even our hobby isn’t immune.

Repeaters
Repeaters are only useful if the antennas can be placed high above ground. In the Netherlands we use a number of existing locations, most of which were once used for analog TV and radio. The owners of the towers decided that safety and security will prevail over (safe, terrorist-free) ham radio.

The following systems will be affected:

• ATV repeater PI6ATV, both analog and digital,
• 2 meter repeater PI3UTR,
• D-star repeater PI1UTR,
• DMR repeater PI1UTR,
• RX co-location for the 70cm repeater PI2NOS,
• RX co-location for the 10 meter repeater PI6TEN,
• Four Hamnet access points and links.

There is a chance that the equipment can be relocated to a lower section of the tower while keeping the antennas on the original altitude. Even in the best case scenario the costs of relocating will exceed the minimal financial reserves – good coax cable is expensive, and we would need a lot of it.

I’ll end with this quote: Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety. (Benjamin Franklin)

As Brick also mentioned in in his last post about Anytone Tech: the reactions on the new models vary wildly. I think Brick said all there is to say, but I’ll add this thought:

– If a radio is cheap but crap, we complain, but buy it anyway.
– If a radio is good but costs more, we complain, but suddenly the price is all that matters.

Let’s see how these radios perform and at what price point before judging them. I know John of Miklor.com gets (or already has) review samples, and I’m on the list too. To give you some more insight in what these radios can and cannot do, here are some preliminary user manuals (PDF).

ANILE-8R User Manual (Preliminary)

NSTIG-8R User Manual (Preliminary)

OBLTR-8R + TERMN-8R User Manual (Preliminary)