Icom IC R-75 comms receiver performance...

[Pigmeat]

Sorry... I'm somewhat skeptical of a bucket of dirt in the shack being even remotely useful as a electrical ground. Maybe you can grow a tomato in it, with enough light? 

Chis, I overwinter serrano peppers that I grow in pots in the backyard indoors under a couple 23 watt CFL's for each. They fruit year round.

Looking-Glass, I used to do some dx'ing at an old family farm you had to hike a good mile plus into to get to the house. The power line to that place went down in a storm in the 80's. There is nothing around it but abandoned farms. The first time I took a portable in that could handle a sizable antenna I was so shocked at the lack of noise I began to wonder if I hadn't damaged the radio on the way in? I tuned to the 40 meter band and found the DX booming in. I was absolutely stunned.

[Looking-Glass]

Pig Meat:  Just goes to prove the "filthy energy" they pump out for domestic use eh? 

Yes, I couldn't believe how noise free the band was while the juice was off while I was on the battery powered Tecsun-2000.

Didn't have this problem when I was living in Sydney as the residential power supply was all under ground.  Reduced the noise further by running a bit of extra lead through the window to the copper water pipe on the wall outside, can hear most of the local NDB's now and quite a number of MW stations not previously noted.

Noticed on Saturday the lethal amount of RF generated through HF from the Fisher & Paykel washing machine too, not to mention the crap from the new Samsung "Digital Technology" refridgerator.

Earth bucket will be ideal for those tomatoes now...maybe Truss would be nice eh?

[pinto vortando]

This is reminiscent of a study done by USN on hf rx antenna traits, they determined that a 6ft vertical over a good ground plane (ie a ship) matched to the line was just about all one needed in many cases.

Josh,
Do you recall the name of the study or the source for this ?

[Josh]

This is reminiscent of a study done by USN on hf rx antenna traits, they determined that a 6ft vertical over a good ground plane (ie a ship) matched to the line was just about all one needed in many cases.

Josh,
Do you recall the name of the study or the source for this ?

Wish I did, I fear it was in one of the myriad 1950s thru 60s qst issues I bought by the box from Ladd Electronics at 41st and Dodge in Omaha during the 90s. I miss that place and the cheap reading! Frank was a great guy. More on topic, it was just a statement that was profound enough for me to memorise it, and it seems to be fairly accurate.

I had that 11m whip up about a wl and it did fantastic from vlf to hf, never tried it above hf. I used a Grove minituner with it for vlf and hf outside 11m. The vlf performance was what amazed me most, but have to mention that part of Nebraska (Omaha) is atop some of the most conduictive soil on the North American continent, so that surely plays a part.

As my hfdf effort gets rolling, I anticipate using some 1/4w cb verticals as the df antennas and will let on how goes it with cb antennas on vlf/hf.

[pinto vortando]

Yes, I couldn't believe how noise free the band was while the juice was off while I was on the battery powered Tecsun-2000.



Noticed on Saturday the lethal amount of RF generated through HF from the Fisher & Paykel washing machine too, not to mention the crap from the new Samsung "Digital Technology" refridgerator.

Just when you think you have solved the noise issues, a new piece of digital garbage shows up …

[pinto vortando]

This is reminiscent of a study done by USN on hf rx antenna traits, they determined that a 6ft vertical over a good ground plane (ie a ship) matched to the line was just about all one needed in many cases.

Josh,
Do you recall the name of the study or the source for this ?

Wish I did, I fear it was in one of the myriad 1950s thru 60s qst issues I bought by the box from Ladd Electronics at 41st and Dodge in Omaha during the 90s. I miss that place and the cheap reading! Frank was a great guy. More on topic, it was just a statement that was profound enough for me to memorise it, and it seems to be fairly accurate.

Got an ApexRadio vertical here, works amazingly well for basically a 6' piece of wire.

[Pigmeat]

I saw an article in a late 90's QST of a vertical with a capacitive hat mounted on mast in an approx. 10 yd. in circumference, 3 ft. deep tank of salt water by the gang from Newington. It may have been 15 ft. tall if that much. They designed for both transmitting and receiving and the published results showed excellent performance up and down the bands.

I've often wondered if you couldn't do the same with a kiddy pool for listening?

[Josh]

My friend who has the wall of JRC gear swore by slopers and HAM hf band verticals for swl. He used some kind of ground enhancing chemical that didn't kill the grass, and watered it every few days. Being at the time just south of downtown Omaha, he had a gigantic noise floor and fought for every scrap of signal he could get.

On the nutcases from Newington, if they'd replaced that tank of salt water with a similar sized sheet of copper or a pipe I bet they'd have gotten the same sig strength readings. I can see my friends case working irl but not Newingtons.

[Looking-Glass]

So far I am very happy with the Icom IC-R75 comms receiver, has nice audio when connected to the Yaesu SP-5 external speaker with filters, especially on MW and SW on AM mode.  Does seem to be a fraction weaker on NDB band though, something 319 report on Icom is around 419 on the FT-2000D to the human ear.

Prefer the Yaesu on CW mode reception though, for some reason, maybe used to the Yaesu more?

Seems to be around an 'S' point to and 'S' point and half down on signal strength with local NDB beacons on LW compared to the FT-2000D, but then again there are a few thousand dollars difference in price between the two radio's. Could be meter calibration too, Yaesu FT-2000D has analogue meter compared to bar graph on IC R-75.

It always happens, when I bought the IC R-75 a friend in Victoria offered me his Yaesu FT-1000MP secondhand for $650.00, he has had it since new and has books and box etc, tells me it has a cracking receiver on the NDB band too...oh well, thems the breaks I guess. Could buy it as a spare set?

Thanks everyone for your hints, tips, pros and cons concerning the R-75, all appreciated and taken on board...now to get rid of that pain of power line noise, that's another story...

[Pigmeat]

Josh, I used to love slopers when I was pirating along with the upright "L", a variation on the dipole w/ similar characteristics. 5 minutes up and down, perfect for mobile pirating, and great for listening as they don't pick up nearly as much noise as a standard vertical but they have enough of it's characteristics to pick up low angle signals well before other antennas.

[Josh]

Wich brings up another point related to USN antenna studies, slopers, and so on. Most people I know who use the t2fd used it as a horizontal antenna and they say it sucks. Apparently one needs to slope the t2fd to get the best performance out of it. The t2fd was created at the Naval Research Laboratory far as I know, becoming a fav at shore stations and NSA both.

I'd definitely unload the r75 and get the ft1000 if had the chance. I didn't like the wooly audio of the 1000 I played with for a few minutes, but there are few rigs that can compare to its signal handling abilities and filtering.

[ChrisSmolinski]

Slopers work very well, my 43 meter folded dipole is mounted that way. 

I had a T2FD for many years, it was about 130 ft long, and mounted sloped, which as Josh pointed out is what you want for best performance. Due to the length, it was probably not as sloped as was ideal, but it was still a good performer, especially on the lower bands. As with other loop style antennas (that is, a continuous piece of wire, I'm including folded dipoles in here as well) they often have lower noise than dipoles.

My 20 and 10 meter dipoles are not folded, but noise is often less of an issue (for me anyway) on the higher bands.