Messages

46

General Radio Discussion / Re: Russia briefly detains, deports US broadcasting chief

« on: July 13, 2016, 2007 UTC »

so does this mean the new type of "cold war" stuff from the 70's & 80's is now going to be through the internet instead of shortwave ?
because it sure looks to me like the tensions building up is leading to another one.
i sure do miss those "cold war" days of stuff on shortwave back then.

47

General Radio Discussion / Re: FCC Pirate Radio Efforts Increase But Fall Short

« on: July 13, 2016, 1556 UTC »

the survey indicates that a legit radio station 85+ miles east of NYC who is operating as a "sister station" for 102.3Mhz at 95.3Mhz to cover reception efforts to the far east of 102.3 at low power level and a small contour, to say that a pirate broadcasting in NYC on a directly adjacent channel of 95.3Mhz, thats causing "interference" is utter BS.
NO ONE in NYC can receive WHFM 95.3Mhz at 5KW on a vehicle dash radio in NYC, it fades out completely at 40 miles from its TX site location on a vehicle dash radio.
you can just barely receive 102.3Mhz at 6KW in NYC, if you hit the right "spot" with your vehicle, you *could* get decent reception less the pirates on the same channel but its certainly not good enough for the casual driver, the tower for 102.3Mhz is about 35 miles east of NYC, the tower for 95.3Mhz is about 85 miles east of NYC.
exactly what are the FM pirates hurting here that is causing the issue ?
the survey talks about RF radiation exposure, really ?
what about all the other antennas in NYC that are not associated with pirate FM radio that are transmitting with hundreds of watts and are located on top of apartment buildings and building towers ?
do they magically not count for RF radiation ?
this is about "interference" to the bottom line $ and not about "interference" to RF signals of which the latter would obviously be much more important had it not been for the cash-cow media conglomerates sweating bullets at the pirate competitors below their feet.

48

SDR - Software Defined Radio / Re: SDRPlay

« on: July 07, 2016, 1835 UTC »

I have had bad experiences with SDRPlay but I see that many people are happy with it. What am I doing wrong?
I have also an SDR-IQ and I've never had these problems.
SDRPlay is full of ghosts signals for me. I use mostly in HF SDRPlay but this is full of ghosts signals and probable intermodulation.
Antennas are Yaguis and dipoles and I've used for years without problems. This same antennas with SDR-IQ have had no problems with ghosts or intermadulacion.
Casual listeners in VHF / UHF show a more acceptable performance. Antenna was a Discone.
I´m losing some adjustment in SDRPlay to improve the work in HF ?
Thanks in advance.

Tony

i generally find lowering the RF gain in small increments until the issue of images and inter-modulation from nearby strong signals is resolved.
i find the SDRplay has a great RF front end being extremely sensitive with a great signal to noise ratio but the downplay is the front end being overloaded by nearby strong signals within 1Mhz of the same band.
if you are using "SDR Console" on the SDRplay, you may find better results by adjusting the VFO to be about 20Khz from the center for HF.

49

Equipment / Re: Effects of modification to gutter antenna

« on: July 03, 2016, 2154 UTC »

You can certainly try and see how things go, even making a loop out the the gutters/wire. Some of the issues presented are just where your likely listenership is, if there's not much but farmland in certain directions you might not get many rx reports from them. Also, at 25 ft up you can expect nvis propagation on the 6.9xx band, wich means coverage from down the block to about 600 miles or so, the plus side is no gaps.

I know it doesn't seem like it should work very well, but I've managed to hit even Western Europe on a good night.  I like the idea of a proper dipole, as others have recommended, but I need to keep very stealth.  The HOA cops are probably the biggest problem.  I've got no trees to string anything up to, and even if I did somebody would notice it almost immediately the way everyone's houses are stacked on top of each other.  The thing I like about the gutter is as far as any Nosy Nellies are concerned, it's just a gutter.  

understood but the thing of it is this and please dont take this the wrong way, while i do not know if there are nearby neighbors and whether their electronic devices are affected or not by any spurious emissions that may be emanating from your TX setup and not knowing the dBmV and frequency of those spurious emissions, i would still have some concern especially if your own electronic devices are affected (your garage door opening/closing), you could reasonably assume that some of the electronic devices of anyone that is nearby, may indeed be affected just as well as yours, and that is something i would use caution about, because its not so much that broadcasting on SW that may get you in trouble, its the interference that it may cause that will get you into trouble.
even though you would be TX'ing after "business" hours, there still remains the chance and possibility of being discovered (an ARO possibly residing in the community).
just my two cents of advice.

50

Equipment / Re: Effects of modification to gutter antenna

« on: July 02, 2016, 2046 UTC »

Question for the experts here as I don't have access to antenna modeling software (nor would I know how to use it).  I'm currently broadcasting off an approximately 40' long aluminum gutter mounted about 25' up on the side of my house.  One end points due north and one end points due south.  Coax is connected via 25' high aluminum downspout.  Coax shielding connected to about a 40' long counterpoise stretched across the back yard.  Whether this setup behaves more like an inverted L, or a dipole, or simply a vertical...I'm not really sure.  

In any case, my reception reports seem to be mostly directional to the east of me, with some reports to the north (but it's a pretty close station).  On the north side of my house I also have an aluminum gutter that's about 30' in length.  I've been thinking of getting up on the roof and running a wire from the north/south gutter to a connection on the east/west gutter.  Mostly as an experiment, but also just to see if it makes my signal a little more omni-directional.  For you folks who understand antennas far better than I do...any idea whether this modification would do anything for me?

am i to understand that you are using the rain gutter that is horizontally mounted alongside the edge of a roof as the antenna or is it something different, like you are just using the actual gutters themselves on a separate mounted platform or held up in the air as the antenna ? (im trying to visualize this)
i would also vote for moof's suggestion, a basic dipole, center fed 12GA copper wire, each side cut at about 35.5 feet for 1/4 wavelength 6.925Mhz, with a 1:1 RF current choke rated 25% above your average output power placed at the center feed point using RG8X coax as the feed cable run from the TX and an antenna tuner to fine tune any mis-matches (because SWR will never be perfect on a narrow band dipole)
here is a simple calculator you can use to get wire lengths for a dipole antenna http://www.onlineconversion.com/frequency_wavelength.htm

51

Equipment / Re: worrisome symptoms from recently repaired Ameritron

« on: June 28, 2016, 2022 UTC »

the important thing is to consider the maximum HV plate current the HV transformer can supply.
i think for this model it is 550mA at its max, and that is for intermittent use of less than 1/2 hour.
if you wanted to do continuous use @ 250mA, you would need to do some modifications to keep the HV transformer cool.
there are a few ways you can keep the HVT cool.
1) placing the HVT in a large can (with heat dissipation plates) of mineral oil.
2) modifying and improving the air circulation by three-fold on the amp with the amp operating in a temperature controlled environment set at 70F (keeps the tanks and tubes cool).
3) not operating at more than 250mA plate current continuous.
ive got a good idea the first time it "blew up", the HVT shorted from excessive heat and possibly destroyed the filament on one or more of the tubes.
generally, the first component to fail on these "compact" triode amps is the HVT, especially when the amp is operating beyond its tolerant duty cycle.

52

Equipment / Re: worrisome symptoms from recently repaired Ameritron

« on: June 28, 2016, 1742 UTC »

is this the AL-811H or just the AL-811 ?
what brand, part number and how many tubes are being used and are they rated CCS or ICAS ?
are you using 120VAC or 240VAC ?
what is your plate and grid current when you are using the amp ?
the next time you operate the amp, take a baking thermometer (the one with the point on the end) and place it at the vent exhaust for about 5 minutes and post back the temperature it reads.
additionally, after you are finished using the amp and its turned off, unplug the power and let it discharge for 60 seconds and take the cover off and touch the metal and wire wound sides of the HV xfmer and see if its blazing hot to the touch, if it is too hot to hold your finger on it, then you will need to reduce the power output of the amp.
the additional heat may be coming from the HV xfmer.

53

Shortwave Broadcast / Re: A Very Unique DX Location...

« on: June 26, 2016, 2157 UTC »

[edited]
never mind.
you are camping out at an old AM radio tower.
(that answered my question about what was on the left side)

54

General Radio Discussion / Re: Do these poor conditions last all summer?

« on: June 21, 2016, 1744 UTC »

i can tell you that propagation during the daytime for VHF and UHF is quite excellent during the summer but non-existent during the winter.

55

Shortwave Broadcast / Re: UNID 6870 AM 2315 UTC 21 MAY 2106

« on: May 21, 2016, 2342 UTC »

6870 AM is a Habana spur/mixing product....I wish it would go away

ahh, thanks for that - i should have known better but the weekend wine must be taking effect 

56

Shortwave Broadcast / UNID 6870 AM 2315 UTC 21 MAY 2106

« on: May 21, 2016, 2321 UTC »

been hearing this fade up and down in the noise level with the quick occasional peak to S5
2320 - UNID music and heard an OM speaking but cannot understand
2321 - "thumping" bass music
2324 - heard OM speaking, sounded latin american.
2331 - sounds like latin music, over modulated with distortion

57

Other / Re: UNID 6920 ~ 6966 0338 13may16 UTC

« on: May 13, 2016, 1502 UTC »

out of curiosity, can you post a waterfall screen shot ?

58

General Radio Discussion / Re: WRMI move from 6915 to 6855 due to complaints from MARS

« on: May 13, 2016, 1500 UTC »

the man is what, 83 years old, this isnt going to last forever.
i can ponder about what will happen to the commercial US SWBC's once he has passed on, since he is their major source of operational income.

59

General Radio Discussion / Re: WRMI move from 6915 to 6855 due to complaints from MARS

« on: May 03, 2016, 1800 UTC »

i didnt think WRMI would last very long at 6915 though i remember that i have heard MARS around 6800-6900 at some point late last year.
i got my money on WRMI not lasting very long at 6855 either.

60

Shortwave Broadcast / Re: Marion's Attic WBCQ 7490AM 5/1/16 2100z

« on: May 01, 2016, 2135 UTC »

You might want to send that shot to WBCQ.

ive spoken to Allan a few times.
he is either lazy, stubborn or doesnt have the funds, nothing has really changed.
at least the TX is closer to frequency this time instead of the usual -100Hz from center, its only -15Hz this time, not that it really matters but most SWBC stations follow ITU specs, Allan isnt one of them