HFU HF Underground
Technical Topics => Equipment => Topic started by: RobRich on September 16, 2019, 0507 UTC
-
I am not an amateur operator, but the recently announced Icom 705 looks interesting. Small footprint, 0.5-10w output, spectrum display, GPS with logging, D-star, micro SD recording, direct sampling, etc.
https://www.universal-radio.com/catalog/hamhf/0705.html
It is not exactly a direct Elecraft competitor on some features and outright size, but I suspect... err, hope there would be a substantial price savings compared to a KX2 anyway.
Also the use of an off-the-shelf Icom battery pack is welcomed IMO, especially if one already has a compatible Icom handheld. Less hassle and easily swappable compared to an internal battery.
On the potential downside, there is no integrated tuner. Tuned lightweight dipoles and similar are easy enough to transport for most popular bands IMO, but I get the appeal of an internal tuner for portable operation. Got to load up a beach chair, light bulb, unknown length of unknown wire, etc. somehow. :P
-
The radio was unveiled at the Tokyo ham fair. I heard the price point is going to be around $700.00. It is true though that with all the features it doesn't have an internal tuner. This would be nice to have especially when working in the field. I guess you can only put so much in one box though. This will be competition for the Yaesu FT-818/817. Especially for the Icom loyalists.
-
I kinda wish they'd made separate qrp rigs for hf and v/uhf like the 7300 and 9700. Make the hf with an internal tuner, the v/uhf version without a tuner.
-
I have seen commentary about the $700 or so expected price point. If so, that is not too bad IMO.
Looking at just the receiver aspect, the older and now discontinued R-75 floated around $550 to $600 new. It is a great desktop receiver for the price, but it also is a ~20-year-old design at this point.
For potentially another $100 or so, the IC-705 gets ya' a direct sampling receiver, various DSP-based options, integrated spectrum display, digital recording, rechargeable battery, etc.
Curious if LW/MW performance will be similar or better than the direct sampling receiver in the IC-7300. IIRC, its receiver sensitivity (and/or selectivity?) tends to roll off at the lower frequencies.
-
Believe me from years of transmitting in the field, used hamfest tuners are cheap and easy to use. Check under the hood for signs of arcing. If it's clean and there is no ozone smell, buy it. You can usually pick them up for around ten bucks. They'll handle wire, twin lead, and coax.
BTW, they've got knobs, the true secret to being heard halfway around the world on 500 mW's.
-
Not that I have much use for them, but I have a couple of L-match and T-match manual tuners.
It is just kind of annoying to have to lug around yet another device. On the plus side, at least a (decent!) dedicated tuner should offer more matching headroom than the typical onboard autotuner.
BTW, spare parts bins aside, I just noticed there is a simple QRP T-match tuner DIY kit floating around eBay. Only 30-300 ohms at up to 15w, but only ~$12 shipped as well.
-
I have run LDG auto tuners for the last couple of years due to a quick match, however I have owned several MFJ tuners and never had any problems with them. Say what you will about MFJ, but there are a lot of them in use after many years.
-
I know people with those LDG's that plan on taking them to their graves.
I've got an MFJ random wire tuner that's as old as many people on this board. I use it with my portable receivers, it works great for hauling in those weak signals. It cost me all of five bucks. I can't remember the model number just now. At the time I bought it figured if I couldn't fix it, I had a nice box and parts to do other nefarious things with.
-
Yup. Nothing like pushing a button and getting a 1:1 match!
-
(Suggesting splitting the thread to "light duty ATU" or alike)
Are those auto-tuners from LDG (or else) useful for receiving only ?
-
They are useful for transmitting and receiving. What I do when for instance listening for pirates on 6.950 I will transmit with my rig on the lowest portion of 40 meters and tune that way. There is probably a way to more accurately tune, but it works fine for me. I do the same for listening frequencies close to other ham bands.
-
(Suggesting splitting the thread to "light duty ATU" or alike)
Are those auto-tuners from LDG (or else) useful for receiving only ?
Most of them require a few watts to run a match, perhaps the ones with front panel L and C controls can be used for rx only stations. In such case I'd just use a common manual HAM transmatch. Or one of these;
(https://www.universal-radio.com/used/UK26Alrg.jpg)
Had one of these for decades now.
Here you can check out designs to roll your own;
http://www.bobsamerica.com/preselectDesignNotes.html
http://www.bobsamerica.com/swl.html
Really want to try one of the 705s, I don't have a dual band rig for home or car and this would perform triple duty as a dual bander (2m/70cm) as well as hf rig in a tiny box, for not much more than one of the good dual band rigs.
Got the G90 updated to 1,7 firmware and MARS modded, fun little rig, outstanding rx audio. Less a tiny Pro3 than a mini IC7800.
https://www.youtube.com/watch?v=jrvDsz0aAGA
-
Does your G90 have 6m TX/RX? I've seen conflicting information online
-
I think I answered my own question. Its basically all the HF bands
-
Sadly the G90 is hf only but they could possibly firmware it into 6m territory if they wished, as the front end and output LC filtering is programmable.
And on that note, I've wanted a IC7800 for ages specifically because Icom said there'd be an sdk, and I guess here it is in a tiny package, the IC7800 I can afford, the G90.
My issue with Icom is they promised a sdk for users of their sdr rigs, where one could fire up the sdk and make changes to the display and other parameters and save them to firmware. I can see why Icom wouldn't want to hand people the ability to brick their sdr by deleting or editing code that shouldn't be, but a sdk that simply allowed safe changes with the ability to always roll back to factory defaults would be great but noooooooooooo, no sdk for Icom sdr rigs. I pray Xiegu does an sdk, and even direct firmware editing for expert users at their own risk.
-
They are useful for transmitting and receiving. What I do when for instance listening for pirates on 6.950 I will transmit with my rig on the lowest portion of 40 meters and tune that way. There is probably a way to more accurately tune, but it works fine for me. I do the same for listening frequencies close to other ham bands.
I don't call that receiving only