Monitoring the temperature of our radios

A lot of modern rigs have a readout, somewhere on the display, of the rig's internal temperature - or that of the final transistors/FET's, etc. Even my mcHF has this feature.

With more and more hams operating outdoors during summer weather, it may be useful to know how warm your radio is getting. Even more so for those who operate digital modes.

Several owners of the FX-4CR have mentioned that the case gets quite warm, even when operating CW at a substantially lower power level than the radio's 20W maximum. My past two activations were with the FX-4CR operating CW at 20 watts and the case got downright hot after 20 minutes or so.

But ambient was 85-90F, so maybe a hot case is to be expected.

A week with the Mercury III S amplifier

If you left an Ameritron AL-80B and an Elecraft KPA-500 in a room together with some wine and soft music, the Mercury III S might be the result. Like the KPA-500, it is solid state and therefore broadbanded - no tuning up is necessary. And, like the AL-80B, it outputs a kilowatt (actually, 1200 watts) and uses a relay for T/R switching.

I've owned both the Ameritron and the Elecraft amps, so the new Mercury feels a bit like a hybrid of both, though it is nothing of the sort.

I assembled the Mercury on the same day it arrived. What initially looked to be a two-evening process took only 5 hours, and that was taking my time. All the parts, patch cables, connectors and hardware went together easily and I think this would make a great first kit for someone.

It was a far easier build than anything else I've ever built and, upon completion, there is no alignment - just a few checks with an ohm meter to make sure various sections aren't shorted to ground.

Rather than a narrative, some brief notes and then some numbers.

Mercury III S amp kit arrives

My Mercury III S amplifier kit arrived today, well ahead of schedule. When I ordered the amp in late May, I was told to expect a four to five month wait until it shipped. After only 2 -1/2 months, here it is. 

Several new reviews for this amp have been added to eHam in that time, all of them giving the kit 5 of 5 stars and excellent write-ups.

Everything is extremely well packed within the 35lb/16kg box with lots of foam protection all around. All electronic parts and circuit boards are packed inside anti-static bags.

Everything about the kit's individual modules exudes quality, from the case itself right down to the RCA interconnecting cables. They are substantial - about the diameter of a #2 pencil - and made to last.

Included with the amp is a 16GB thumb drive containing 3.5GB of data: assembly videos, 62 close-up photos of various construction steps, schematics, BOM, Operator's Manual (20 pages) and, of course, the Assembly Manual (29 pages).

IC-705: 1 watt to 500 watts

With the "IC-705 meets KPA-500" configuration from last weekend's DX contest still in place - and the Hardrock-50 in series - I couldn't help but wonder if I could use one amp to drive the other.

A quick check of the Hardrock-50's manual mentions one way of doing it:

 

Localizing source of QRM to weather radar

I met two FCC technicians today at an FAA weather radar site to assist them in tracking down two sources of interference to the radar. See the back story here. This was a "first" for me and I was very much looking forward to learning what equipment was used and how they go about it.

The techs have a full time job as QRM detectors (not their official title) - they were familiar with ham radio and have experience in tracking down pirate FM stations. We had an interesting conversation as we waited for the clock to hit 1400Z - the time I had coordinated the shutdown of the radar.

Antenna input removed from receiver; spec-an now attached to the N-cable

I had imagined that, with the radar down, they would bring out some sort of receiver with a directional antenna and find the direction to the source of the QRM. I had assumed that the source was more local than it turned out to be and that finding it would be accomplished with the equipment they'd brought with them.

CQ-WPX (CW) results with RGO One

I had intended to use the CQ-WPX (CW) contest as a way of looking at the RGO One's receiver performance in crowded band conditions but my planned "20 minutes here, 20 minutes there" turned into about 11 hours of operating time on all bands 10-80m.

I'll write up my impressions of the radio itself soon but, long story short, the little rig has a fantastic receiver and was a joy to operate. Weak signals next to strong ones? No problem. De-sensing in the presence of numerous strong signals? Doesn't happen.