IC-R8600's Digital Twin Passband Tuning

There is a handful of nearby AM radio stations that are very strong here and sometimes make it difficult to hear stations on adjacent frequencies, for example, WPRX on 1120 kHz running 1000 watts 2 miles away, WNTY on 990 kHz running 2500 watts 5 miles away and WLAT on 910 kHz running 5000 watts 8 miles away. But by far, the worst is WTIC on 1080 running 50,000 watts line-of-sight 16 miles away. Its 50 kilowatts are bad enough, but it also uses IBOC, which dumps hash on 1070 and 1090 that is 20 over 9.

Despite the hash, I have managed to bag seven stations on 1070 by rotating my radios and/or antennas to null WTIC's signal.

I wondered if my new whiz-bang ICOM IC-R8600 could handle WTIC's IBOC hash. Studying the IC-R8600 manual, I thought that the radio's "Digital Twin PBT" might solve the problem.

"The Digital Twin PBT (Passband Tuning) electronically narrows the IF passband width by over wrapping the passband frequency ranges of 2 PBT filters (PBT1 and PBT2), to reject interference."

So I saddled up to the radio last night around 2330 local time, powered up the IC-R8600 and found Radio Havana loud and clear on 530 kHz, so conditions were very good and WTIC's IBOC hash would be very strong. Tuning to 1070, all I could hear was the IBOC hash.

I selected the Twin PBT option and began adjusting the two PBT filters (see figure above). In less than a minute, the IBOC hash gave way to The Eagles singing "Already Gone" on CHOK in Sarnia, Ontario!

Twin PBT did the trick!

Ring of Copper

In 1963, the U.S. launched millions of copper needles into space to try a new radio communication strategy. Months later, the needles fell out of orbit.

View the video that tells all.

Getting in touch with the IC-R8600

I have had the ICOM IC-R8600 for two weeks and I am still learning all about it. The learning curve is not steep... just long because the radio has so many features and options.

This is the first touch screen radio I have owned, so some of the features that I find so impressive might be old hat to folks who are familiar with touch screen radios, especially ICOM touch screen radios.

Anyway, my favorite touch screen feature is the ability to zoom and switch frequency to the zoomed area of the radio spectrum. For example, say I have the IC-R8600's spectrum scope set to display 1 MHz of a radio band and I spot a signal up the band that I wish to tune in.

Instead of spinning the tuning dial to move up the band, I simply touch the spectrum display in the general area of the signal of interest.

The display magnifies that portion of the band.

I touch the signal of interest in the magnified area...

...and voila!, the IC-R8600 tunes the radio to that signal.

Another cool feature of the IC-R8600 is the ability to capture screens like the ones above.

IC-R8600 is not so hot

Before purchasing the ICOM IC-R8600, I did a lot of research. I read all the reviews I could find and in general, most of them gave the radio high marks.

N9EWO's review gave me a little concern, but was not a deal-breaker and I bought the radio despite comments that the radio "runs quite warm almost near HOT after a 3 to 4 hours of operation (especially at the marked regulated 13.8 DC volts, screen saver off)!"

I am using a Powerwerx SS-30DV to power my IC-R8600 and it outputs 14.1 VDC, so in theory, my radio should run a bit warmer than it would at 13.8 VDC.

The radio is warm, but not "quite warm" and is far from running "almost near HOT" after 3 or 4 hours of operation, as well as after 8 to 10 hours. And this in a house with the AC off and the furnace maintaining a room temperature of 68℉.

Perhaps, N9EWO's radio was an early production model and the heat problem was fixed by the time ICOM produced my radio.

In any case, my IC-R8600 is not so hot.

The IC-R8600 and a Tale of Three Antennas

I have three antennas connected to my new ICOM IC-R8600 receiver:

‣ ICOM AH-7000 discone antenna for VHF and UHF

‣ Hy-Gain 18 AVT/WB-A vertical for HF

‣ Homebrew 80-meter inverted Vee for HF

Monday night, I heard a foreign-language station on 1700 kHz. It never identified and after an hour, it disappeared into the noise. Tuesday night, I checked 1700 and the station was there again, but it was much stronger than Monday night.

I switched between my two HF antennas, but there was not much difference. I inadvertently switched in the discone and I could hear it on the VHF/UHF antenna too, but at a lower signal level.

The IC-R8600 seemed to be so sensitive that it could hear HF signals on a VHF/UHF antenna!

I tuned the radio to the LW band. In the past using other radios, I could only hear LW activity with the 80-meter inverted Vee, but with the IC-R8600, I could also hear LW activity with the vertical antenna, but at a lower signal level. I switched to the discone and yes, I could also hear LW activity with the VHF/UHF antenna, but at a much lower signal strength.

Wow! The IC-R8600 is an amazing receiver!

By the way, I finally identified the mystery foreign-language station: Radio Mega, WJCC in Miami Springs, Florida, 1666 miles to the south-southwest. I first logged WJCC two years ago and have heard it occasionally since then, but never as strong as I have heard it with the IC-R8600! It was armchair copy last night.

ICOM IC-R8600

I have been a radio hobbyist for over 55 years and over that time, I have owned a lot of radios. Last Wednesday, UPS delivered my latest acquisition, an ICOM IC-R8600 10 kHz-3 GHz receiver and I believe it is the best receiver I have ever owned. (It should be since it is the most expensive radio I have ever owned! LOL)

According to Sherwood Engineering's highly-regarded receiver tests, the IC-R8600 is number 2  of 132 tested receivers and transceivers [sorted by Third-Order Dynamic Range Narrow Spaced or ARRL RMDR (Reciprocal Mixing Dynamic Range) if phase noise limited]. (The only better receiver is a transceiver.) After using the radio for less than a week, I concur with Sherwood's test results.

And last evening, I logged my first new station with the IC-R8600: WFAT on 700 kHz, a daytime-only operation transmitting 2500 watts from Athol, Massachusetts, 74 miles away.

I am still familiarizing myself with the 8600, slowly working my way through the manual in order to take in all the features the radio has to offer. And I plan to review those features in future installments of this blog, so please stay tuned.

Violet's Radio

This episode of Peanuts from 1953 made me laugh out loud this morning!