I recently posted results from my listening endurance test with the new Icom IC-705 QRP general coverage transceiver. I’ve been on a mission to see just how long the supplied BP-272 Li-ion battery pack can hold up with a full charge in real-world conditions.

Thursday, I took the IC-705 to the field and activated a park using only the charged battery pack. After nearly 2 hours of constant operation (calling CQ and working stations) the BP-272 still had nearly 40% of its capacity.

That’s better than I expected, especially knowing the BP-272 is the slim, lower capacity battery pack.

I have to admit: that was a particularly fun activation because propagation finally gave me a break and I worked stations from the Azores to Oregon on a mere five watts of power.

Click here to read my full field report at QRPer.com.

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The shortwave radio listener part of me might actually be more excited about the Icom IC-705 than the ham radio operator part of me.

The IC-705 has a number of features for ham radio operators who also enjoy broadcast listening. For example, it sports:

a general coverage receiver,
good performance specs,
notch filtering (both manual and automatic),
Icom twin passband filtering,
an AM bandwidth filter maximum width of 10 kHz
built-in digital recording of both received and transmitted audio,
audio treble/bass adjustments,
and battery power from Icom HT Li-ion battery packs

The Icom IC-705 ships with an BP-272 Li-ion battery pack and since the announcement last year about the IC-705, I’ve been curious how long the BP-272 could power the IC-705 in receive only.

A real-world RX test

Yesterday morning, I resisted the urge to hunt POTA and SOTA stations with the IC-705 and, instead, spent the day simply listening.

I started the experiment with a fully-charged BP-272 7.4V 1880 mAh battery pack (the pack supplied with the IC-705). At 9:00 in the morning, I unplugged the IC-705 from my 12V power supply and ran the receiver all day on just the battery pack.

I made some practical changes to maximize play time: I turned on the screen saver, turned off GPS, set the LCD backlight auto adjustment to 2%, and set the screen timer to turn off after 1 minute.

I ran the volume somewhere between low and moderate and only raised it to what I would consider very loud a few times to copy weak signals. I listened to AM, SSB, and FM signals across the spectrum, but primarily cruised the HF bands.

Of course, I never transmitted with the IC-705 during this period (saving that for the next test).

I probably could have done more to decrease current drain, but frankly I wanted this to be based on how I’d likely configure the rig for use on an SWL DXpedition.

Results

I unplugged the IC-705 from the 12V power supply at 9:00 local and the radio auto shut down at 16:39 local: a total of 7 hours, 39 minutes.

Honestly? I’m fairly impressed with this number mainly because it’s based on the smaller battery pack. The supplied BP-272 pack has 1880 mAh of capacity. The optional BP-307, on the other hand, has 3150 mAh of capacity.

If I decide to keep the IC-705, I will be very tempted to purchase a ($130 US) BP-307 pack as well.

Next test: How long can the IC-705 last on battery during a POTA activation?

As early as today, I will see just how long the BP-272 pack can operate the IC-705 during a POTA activation. This will be a true challenge on the smaller battery pack since POTA activations require a lot of transmitting (constant CQ calls and exchanges). There’ll be no lack of calling CQ on a day like today when propagation is so incredible poor.

Follow the tag IC-705 for more updates.

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