Topics

1

General Radio Discussion / Dead End Q vs Z Match

« on: August 17, 2024, 0110 UTC »

Hey All,

Just a theory question, maybe not so modern in origin, but a curiosity.

Back in ancient times, one method of matching the Z of a simple / single tank crystal radio to either the detector or the antenna was through the use tap of  leads run to a panel mounted tap switch.

But this method left all unused leads hanging in dead end effect ,  spoiling the tank Q.

Cases were made that the increase of energy transfer  via Z matching “ could “ (??) overcome the Q hit of dead ended leads into a net “ up” (by HOW much ? ) of RF energy recovery.

I admit, my grasp of this “ battle of the two phenomena “  isn’t as much up to snuff as I would like.

Does anyone envision any physics state that could result in a net “ up” via Z matching, despite being  “ fought “ by Q loss.

I understand the layout “convenience”  of a  front panel tap switch.

But is this ALWAYS an undesirable building technique ?

FWIW, I use a  “hump” of coil turn that slightly arcs up and then back down to the winding.

That way the “ connection point” on the coil doesn’t break the coil plane very much, nor does it have any twists.

A single lead  with a flat ( non toothed ) copper alligator clip is brought TO the coil. Viola, no dead end leads left hanging .

Definitely not as convenient as a rotary switch, but I feel it is probably a more efficient way to go.


Again, just trying to get some theory input on a question that has puzzled me for a while.

de NQC

2

Longwave Loggings / NLK vs NAA de NQC

« on: July 25, 2024, 2105 UTC »

Hey RobRich and All,



I noticed on your LW list you have NLK but not NAA.

In the past I have logged a strong beat note/ data stream on 24 KC for NAA as copied at Boston.

Then a SECOND ( weaker at Boston) beat note/ data stream would rise up from the upper “edge” of NAA . This would occur as I approached NLK on 24.8 Kc.

So the two may be “ blended “ together to a degree, but to sum ,look for NAA JUST A BIT below NLK.

Not sure why the USN put these so close together, but I guess they had their reasons.

Not sure about conditions in FL, but again, if you look JUST below NLK, you may be able to add NAA to your list.

Just figured I’d try and toss another station your way if you can get separate copy.

de

NQC

3

The RF Workbench / Pushing a SHORT Antenna With Loading Coil

« on: July 24, 2024, 0058 UTC »

Hey All,

Kind of between a rock and a hard place.

The only spot on my apartment building property to try a wire antenna is a run limited to 35 ft long and  maybe 9 ft up at  the far end sloping to around 6 ft up at the radio end.

I would like a temporary “ set up, use and then take  down “ type of arrangement for a GOOD double tuned crystal set Dx  use at night, every now and then.


These limitations present a pretty dismal prospect, especially for the low end of the broadcast band.But pretty much all I have to work with.

Ideally 100 ft long and 30+ ft up is what one wants for crystal sets.



“Generally” ,short antennas need inductance (and overly long ones need capacitance).

So I am not sure if there is any role for series variable capacitance anywhere in the feed line .

 

This antenna MAY just be crying out  for inductance only.

 But it as also WAY  off from optimal design specs .

So I am definitely open to other unforeseen factors,ideas and  viewpoints.

FWIW , the radio’s antenna tank coil can be switched for parallel or series variable cap .There is also a full range of coil Z taps for the feed line.

But in the case of a short antenna I understand parallel tuning the radio’s ant coil is the way to go.





Just looking for opinions and ideas as to whether a simple loading coil ( it must be located at the radio end)  is really going to perk things up enough to be worth my while.

I am thinking that trying to goose such a short and low antenna into “ some” measure of improvement simply by inserting a “magical “ / “cure all “ load may really not cut it.

IF ( IF) I did go for it, I would envision something BIG  diameter (2-3 ft ?) with the turns spread out as much as is practical , yet still have a decent inductance.A compromise of turn spacing would be necessary ( ie 1-3” ?).

Is my load design off base?

Maybe a half baked LONG shot, but does anyone have any ideas of even a prayer of improvement on such a crumb ball antenna?

I know receive antennas are FAR less critical vs. transmit antennas.

Yet I still kind of feel like I am really pushing the envelope.

Obviously, I can experiment on my own, but just looking for ideas from other folks.

My ground may end up being a 25 ft bare copper run laid in the garden and kept wet.

So at least the ground return may
be “ good” with a ( hopefully) low resistance.

ANY input is welcome.

de NQC

4

Weather / The Heat is ON !

« on: July 08, 2024, 1808 UTC »

Hey All,

Here at Boston we kind of dodged it for an extra 3 + weeks , compared than other parts of the country. But we seem to be “ in it “  now.

The jet stream seems to have fizzled out or moved North.Only a 50/50 chance for any more rain in the medium length future .

We HAD been doing good in the rain department , up until now. The Boston reservoir is full, so no anticipated problems for homes, but the farms just outside the water district could have some problems later on.

WITHIN the district, they are adding more and more users each year without any additional storage capacity.

So maybe it will become an issue at some years into the future.

We have a “ two” year supply at present consumption.

The only “ up” side is since the heat hit with a “ bit “ of “delay “ , in theory we will “ come out of it “ that much “ earlier “.

But aside from tropical systems we usually don’t get too much water in New England until the Winter and Spring.

So Fall may be “ cooler “, but still maybe dry.

FWIW, I was a 10 year volunteer at NWS Climate Research Station, Blue
Hill( Milton) MA.

I am an avid weather “ enthusiast “.

de NQC

5

Huh? / What Projects and Shout 2 ThaDood

« on: July 03, 2024, 1944 UTC »

Hey All,

(I hope I am posting in the correct area )
 

Just a shout out to everyone
( and especially ThaDood )to see what types of projects ( radio or otherwise) folks are doing or , in general, what’s up for the Summer.

Unfortunately my shop and radio capabilities have been knocked down around 90 %, and on top of that, I now have BIG QRM/QRN issues re newly installed systems in my apartment building.

But I am trying to have fun and working with what I have.

Mostly I am just now accumulating parts for ( hopefully) a better chance at gearing up and “ reopening “ my shop and also do more serious Dxing in the Fall ( maybe).

I have been mostly looking at designs for now.

I want a lightning audio “back up  “ to the lightning/ weather web pages.( Yes, I am actually LOOKING for static crashes)  .

I am a SERIOUS weather enthusiast. The 7 Kc and 24 Kc designs probably aren’t going to work out here for me, so I may just “default “ up to 150 Kc.Right now portable barefoot I am good on storms for around 90 or 100 miles during the day. I’d be happy IF I could double that though.So maybe a compact 150 Kc loop inductively coupled to the ferrite inside the  portable is in order.

Also looking at doing some quick receivers  for B’cast Band ie maybe a regen and a “ high “ performance crystal set, etc, etc.

Nothing big or fancy, just for some quick simple giggles.

Right now (receive only)  HF at my QTH is  “ OK”- with a indoor 40 M “quarter wave “ well stood off on ceramics onto all four walls of the bedroom.Thankfully the building is made of wood.

It’s “ decent “ when prop is up.
Summary: Fair on 75, “ better “ from 60 to 25 , gradually drops off higher. But it will grab 11/10 IF they are really up.Poor  below 75.But obviously the ant is crazy short and compromised down that low.

Bcast Band  is on external loops coupled the factory built receivers, WHEN I can dance around the computer hash that now blocks a lot of my former Dx favorites.Especially down low in the band.

Recently I had LOTS of fun copying Radio 48 /MRI on 6870. I have copied maybe 4 or 5 stations up around there over the last 3 or 4 months.So the quarter wave CAN  come through IF the prop does it’s bit as well.

The gear here now is  just a bit of home brew stuff and an ATS 803a and a Dx 440 .

But doing my best to “ keep the sunny side up “.It could be worse.

What are YOU folks up to ?

de NQC

6

MW Loggings / 650 WSRO (MA) Gone Dark (?) WSM Good Instead

« on: June 23, 2024, 0257 UTC »

Hey All,

Local WSRO  over the last year or so had been on  air  normally , then off for a while, then digital, then off again  ,then digital  for maybe 4 months recently, now QRT ( for good ?). Tonight 650 was WSM , with a fairly good signal. Many times SM is either MIA or poor here.

SRO has thrashed  for 5 or 10 years around trying to "find itself" (and an audience). The station was Brazilian, then a  kind of  odd music mix,    tried digital, then  went QRT for a while . Then the owner passed away not long  ago  and someone put  it back on ( digital), which apparently didn't work out.

I know that SRO certainly had the license right to operate ( even if the DID forget to turn down the power at night) and that SM is NOT protected this far away (Boston).

But they blocked one of my favorite DX targets (SM)   , no nulling possible, both were in the same direction.

But  to me it was kind of "whatever"- when they were running ANALOG. But when they went digital (TWICE) , they kind of went into a "jammer" status, blocking SM with programming that almost NO ONE was listening to.

I really don't like to see any  station fail, but I really won't miss this "digital  incarnation" either.

Other prop odd tonight, again SM  pretty good, yet a number of NYC's either poor or not there.

1570 had a tin can from somewhere- two NY state stations listed as 442 and 500 watts- no big night time high power  listed on frq for anybody. It could have been a further  away flea  as well. But no id.

Local WMEX (100 W, 9 mi , omni ant) .It has a HUGE  hill very close to me in the way. Usually fair or better though. Tonight nada. Weird.

Generally odd prop tonight, some pretty long Dx was good,  others MIA. Same deal on the shorter stuff (less than 200 or 300 mi).

Fun session though.

de NQC

7

MW Loggings / NYC- Boston- NH Daytime "Study"

« on: April 29, 2023, 1524 UTC »

Hey All,

Yesterday I took  a road trip to NH to the big ham radio flea.

I left MY Boston QTH (Bos -NYC  215 Mi) at around 0700 local .

Notes :

Stayed with 880/WCBS  on car radio the entire way up. Initially  I encountered a good deal of 1st adjacent QRM from local WAMG 890.The car radio seems to play kind of broad. This QRM    gradually went away as I proceeded North away from Boston,as expected .CBS's occasional ( sometimes deep) QSB also pretty much went away while  traveling North- ODD .

AT Deerfield ,NH (277 Mi to NYC ) 0900 local  in huge RF quiet open field :

660 WFAN fair to good.
710 WOR fair.
770 WABC fair to poor.
880 WCBS  VERY GOOD.FWIW Their "fringe" pattern contour is "depicted"  as being on the MA/RI border.So QUITE a ways beyond that !
1010 WINS - nothing heard.   WCNL  NH 10 Kw from a "short" tower  copied instead.
1130 WBBR poor.

Kind of cool to receive and compare  day time signals over some of the least conductive ground in the US (although admittedly , all @ 50 Kw). I am sure it's not  an overly spectacular distance record  , but was fun.

I wonder how much further North before before these (especially WCBS ) start to get into trouble.

K

8

Huh? / Bizarre Russian Message: Swan Lake / Swan Song

« on: March 10, 2022, 1657 UTC »

Hey All,

Group W seemed to be unavailable, so I hope this is OK here.

Recently independent  Dozhd / TV Rain Russia signed off under intense pressure from Putin.

After the staff walked off the set, the station began to play an old short video loop from Tchaikovsky’s Swan Lake Ballet.

Apparently, this was an old signal that the Soviets used to prepare the masses for big news, re instability or leadership change.

The loop was of ballerinas dancing for around a minute. It would be played over and over and over again for hours  and hours and hours on Soviet state TV and radio.

This was done during the 1991 Russian coup attempt, and the deaths of Brezhnev, Andropov and Chernenko.

Obviously, TV Rain co-opted the old Soviet warning as their notice to the Russian people that the country was in BIG trouble.
 
Swan Lake represents a “mourning for broken dreams, sadness  for opportunities lost or regrets for unfulfilled plans”.

Who thought of using Swan , KGB psyops?
 

For Russians, it’s a kind of EAS/ EBS warning tone played on flutes and violins.Everyone knows what this video means.

I find this procedure almost bizarre, and there certainly is no counterpart to in in the West.

When JFK was shot , TV just broke right in. We didn’t need to prepare ( or warn certain people in the country) that something big was happening. We just did it.

Again , strange.

K

9

MW Loggings / WSM (BARELY) Under Digital Station

« on: December 16, 2021, 1211 UTC »

Hey All,

Log from earlier this week : Copied WSM under the regional  digital dog WSRO 650 . Specks  of voice and  a rhythm beat  for for a bit ( sounded like a good ole country bass).
SM/SRO are nearly on the same bearing to me , so some hash had to be let in or no joy. Radio placement  / loop aiming geometries  were among the tightest I have ever encountered, super touchy and  extremely easy to lose.

I suppose the take away here is it can be done (in "theory" !) , but would take a LOT more horsepower from the analog station to "break through". Even then , not sure how listenable things would be.

Nice to hear a tiny peep from "The Legend " , but overall a colossal failure.

Also FWIW, a  tiny BIT of SRO  hash QRM to fair CMLA 640 and  strong WFAN 660, but not enough to really affect things.

640 in particular is one of my favorite Dx frequencies.

K

 

10

MW Loggings / Excellent Conditions On AM

« on: November 17, 2021, 1253 UTC »

Hey All,

Summary  from last night , 0400 UTC onward :

Highlight : CMLA 640 Cuba up to a very rare  high signal level . Never a common station ( even in  winter ) , it was up to 3/4 scale ( WITHOUT Select -A Tenna  ) on the ATS 803a ( which is "sensitive" , but has a   ferrite bar that is shorter than desired) . Near full pin when  S-A -T was used and, at  times, actually made it worse (unheard of  for this station !). Some rapid QSB  at times  but pleasant enough to copy music for long periods.

Yet- NO traces of  Radio Reloj CW  from CMED 570 or CMGD 870 despite   a big  digging effort  with  the atomic clock to line up RR cw id's  exactly on the minute. You can't have everything ! . Odd, with the  Cuban path seemingly open , I would have expected at least CMED. Nope.

WSB 750 GA up strong  ( a rare word for them). SB is my normal  "deep fringe" station during "average" conditions.
KDKA 1020 PA elbows BZ 1030 and INS  1010 right out of the way. No trace of QRM from either. DKA usually only "mediocre" here.
WHO 1040 IA good ( another rare word)

The usual  Eastern US 50 Kw suspects throughout  the band busting in  at stable arm chair copy .

LOTS of activity from lower powered Dx  stations on frequencies below 1000Kc  that are usually not so hot,  too many to wait for Id's.

Pile ups  of MANY outlets on grave yard frequencies, MUCH hotter than normal  .

 My ATS 803a does not do X band  , but  it was the  "receiver of the evening" , having "some " advantages  over the Panasonic 840. So I went with  it for the entire session. The Pan is actually better for listening to isolated long Dx  stations (IMHO), but the Sangean is digital and has a BFO , so it's  better for fast paced sessions  that bounce around the band and for seeking  RR CW Id's.

K

11

MW Loggings / CMED Cuba (Radio Reloj) - Very Good Conditions

« on: November 11, 2021, 1406 UTC »

Hey All,

11/12/21 0300 UTC

ATS 803a , Select- A Tenna

518 Kc NAVTEX , fair to weak  ,unknown  QTH

570 Kc CMED Cuba  in SSB mode  very weak CW id's (behind WMCA  NY and possible  WWRC MD). Not heard Reloj CW in years !

640 Kc  CMLA Cuba up to fair (or better)   (in AM mode). Best in a while.

1020 Kc KDKA PA. Good copy , no prob from  adjacents  WBZ 1030 or WINS 1010

1040 Kc WHO IA good copy , no prob re WBZ

LOTS else happening , just the highlights here.

Tried for 870 CMGD Reloj,also an old favorite, but no luck this time.


Earlier  this  week    :

A  propagation slump late last /early this week  / ,  then MW back up Wed 11/ 10 /21.

Sloppy log  :

CMLA 640  up to fluttery  fair  or a BIT better  (for a while) then  it receded back into the mud.

WHO 1040 up stable  to fair or better , then it too slipped away.

The X band made an "OK"  showing  -  (with the "usual" East Coast suspects  ie WPTX 1690, WRCR 1700, etc). Some  came in fair   , but more  leaning toward the poor ( but still audible ) side  of things.

Pan 840 rcvr   w /Select -A Tenna in noisy apt.

K

12

Utility / Things Are "Up" ("Sort Of" )

« on: November 11, 2021, 1340 UTC »

Hey All ,

Yesterday afternoon  (via HFU SDR)  WWV good on 10, WWVH fair  on 15 / WWV good on 15, WWV good on 20  and (drum roll) WWV still up and good on 25 (!).

12, 11, 10 did not happen despite Dx maps depictions of activity.

Other  "non utility" ( ham , SW BC, MW BC, etc)  stations are   back up as well after a slump.

K

13

General Radio Discussion / 1710 CHIM Radio vs Canadian "Official" Top End at 1700-1705 KC

« on: October 10, 2021, 1647 UTC »

Hey All,

Anyone know anything about  1710 CHIM ,ONT, Canada ?

Supposedly 84 watts. Yet the Canadian spectrum assignments list the TOP frequency as 1705 Kc ( 1700 centered), just the same as the USA .

The only known  North American  exception above 1705 Kc  I know of is  WQFG 689     centered on 1710 Kc in NJ.

Special permit ? Pirate  outlet  carrying  their licensed FM operations ?

Hmmmm,

K

14

Shortwave Broadcast / Things Picking Up a Bit ?

« on: October 06, 2021, 1337 UTC »

Hey All,

Not so much specific loggings, but a general comment  I have had some People's Rep of China  regionals  on  morning Gray line the last few days , especially in 31 M. One or two actually fair or better.

Supposedly gray line isn't cycle related , but it's SOMETHING  in what used to be  pretty quiet band. Other "non gray"  bits  and pieces rolling in as well. Things SEEM to be picking up , at least a BIT. Things were flat, dead buried here until  very recently.

Right now, I am just running a Trans Oceanic on the built in telescopic antenna  in a noisy apt.

So if I (!) am starting to copy stuff, I imagine those who actually have REAL antennas may also being hearing that much more now  (I would think).

How is everyone else doing on HF ?

de K

15

MW Loggings / New Transoceanic Shootout w/Sangean 803A

« on: September 06, 2021, 0126 UTC »

Hey All,

Compared my recently acquired T/O 3000-1 (please see HFU General Radio Discussion) with the venerable and sensitive Sangean 803A.

9/5/21 2330 UTC

560 WGAN weak.                   Tie T/O  vs 803.
570 WMCA fair/weak.            Tie T/O vs 803.
580 WTAG QRM from 590.      Advantage 803 in narrow mode.
610 WGIR fair.                        Advantage 803 in wide mode.
770 WABC strong.                 Tie. Good music on  Joe Piscopo show.
1610 CHHA weak.                   Advantage T/O

0100 UTC :
1020 KDKA fair in QSB.           Tie. NO QRM from 1010  and a tiny bit from  1030.

(FWIW, KDKA is often  a tough  catch at this QTH. If a rig here has good 1020 Kc separation from local flamethrower WBZ on 1030 and  night time biggie WINS on 1010, it's considered pretty good).

Overall : Fairly close in performance. The T/O has  bright and crisp audio, a real pleasure to listen to. Mechanically it has a rock solid  and bullet resistant feel to it. A really nice addition to the collection and a  great keep sake from Cuttyhunk  Island.

K