Messages

61

Part 15 AM and FM Station Operation / Re: Coax to use

« on: August 06, 2022, 0613 UTC »

I've used the off brand lmr cable with good results.  I've been using off brand half inch super flex on projects lately also without incident.

+-RH

62

Part 15 AM and FM Station Operation / Re: Coax to use

« on: August 03, 2022, 0653 UTC »

Agreed.  For runs under 50 feet, lmr240 is fine.  I use it for short cellular jumpers without issue.  Anything longer though, I'd use lmr400.

+-RH

63

Part 15 AM and FM Station Operation / Re: New $69 laptop good for Ham (or solar Part15

« on: July 25, 2022, 1816 UTC »

Nothing new under the sun.  I had an old net-top laptop about a decade ago I bought for the same purpose.  It wound up being a surfing laptop for the garage and the tub.
I'm sure it's arm based to run that low on the consumption end, so don't expect a speed demon.

+-RH

64

The RF Workbench / Re: Beyond 45/48m

« on: June 14, 2022, 0247 UTC »

Your not reading again stretchy.  I am talking about 1700v devices with 80mOhm RDSon...not 900v devices at 280mOhm.

The current rig has run up to 10 Mhz.  I have little interest in anything much above that as I don't operate during the day.  Bolt on fet drivers are used to deal with the gate capacity.  I will explore GaN when the price performance ratio gets more attractive.  For now Sic makes more sense in my topologies and power levels.  If they come out with comparable high voltage GaN devices at a reasonable price, I'll consider it.

I like my current approach as it affords high power with a simple low cost PA architecture.  There are ways to get similar power with lower voltages, but circuit complexity, the headache of ferrite, high current losses, etc start to make things unnatractive for my needs.

SiC devices have made what I'm doing possible at much lower cost, and simpler design than was possible just a handful of years ago.  GaN for the moment, does not hold the same advantages.

+-RH

65

The RF Workbench / Re: Beyond 45/48m

« on: June 12, 2022, 1424 UTC »

MSC080SMA120B

+-RH

66

The RF Workbench / Re: Beyond 45/48m

« on: June 11, 2022, 0507 UTC »

The current transmitter has C2M0080120D's in it I believe.  Mouser has them in stock again, but the price has gone up.  Microsemi/Microchip have comparable ones are a little cheaper (half) and have lower gate capacity.  I have not tried them in a circuit though.

+-RH

67

The RF Workbench / Re: Wanna' communicate, and broadcast, with light? It can be done!

« on: June 11, 2022, 0431 UTC »

Complements of Max M Carter, who has a cool radio hobby website as well;

Music on a light beam http://maxmcarter.com/lasrstuf/laserexperiments.html

+-RH

68

The RF Workbench / Re: Beyond 45/48m

« on: June 10, 2022, 0339 UTC »

In the modern era of 56V power tools, higher voltage operation is no longer a challenge.  My Ego trimmer has enough battery on it to run a 50 watt transmitter for over two hours, and recharges in 15 minutes!

I too have had reasonable success with CMCD since 2017 and have been running with Cree 1200V devices.  They have even survived a few moments of stupidity with VSWR easily over 2:1 at rated power.  I am now eying Microsemi as they have 1700V devices at reasonable cost, and in stock.  This should facilitate 2KW carrier or greater in one PA with two devices.  Time will tell, as prototypes are in the works.

+-RH

69

General Radio Discussion / Re: Does anyone still have a Franken-FM by them?

« on: June 01, 2022, 1720 UTC »

https://www.youtube.com/watch?v=jlYQ-abUN9g

+-RH

70

Huh? / Re: So, what's up with all of these NOAA Weather Radio outages?

« on: June 01, 2022, 1714 UTC »

Oh yeah!!!! I've always thought that made some nice sense to have a Weather FREQ broadcasting on the AM BC band. Well, if that is indeed a LPB AM-5, unless that took a big lightning hit and fried that, a decent tech shouldn't have too much trouble replacing anything on that transmitter. Even if a new crystal is needed, a DDS oscillator will do very nicely on that. I know this, since a friend of mine is running his AM Carrier-Current station with an AM-5 and a DDS OSC for his selected FREQ. So, far, rock solid for 8 years with him on that. So, can be done.

You're dealing with Canadian government.  These are the people that are so uptight that when a new station signs on, they have to have a representative from IC come out and sign on the transmitter.  I highly doubt they will retrofit an old transmitter with parts that would void its type acceptance.

+-RH

71

North American Shortwave Pirate / Re: Radio 48 via MRI 6860 USB 0033 UTC 29 May 2022

« on: May 29, 2022, 0307 UTC »

0306z 6860KHz USB "I used to suck dick for coke" 
Caught the end of it, including 'You can do magic' by America, and other 80's and 70's soft rock.
0318 Paramore 'I Caught Myself'
0319 Finest Sound MRI ID into 'What I Am' by Kai jack, a cover of Eddie Brickell
0322 MRI Proper People ID
0331 MRI Best Music ID into 'Games Without Frontiers'
The signal is doing very well tonight on a midsouth Kiwi, averaging about S9+10.
0335 MRI less BS ID, into Der Commisar'  Mix has really upped his game with the ID's 
2240 an old mix classic 'Back Into My Heart' by Chris Botti.  Love it!
0344 'The look of Love' also by Chris Botti.  Thanks brother!
0349 MRI ID into 'Eyes Without A Face' Billy Idol
0412 MRI ID into a track by Chicane, if memory serves.  Playing a bit of around the world myself.  Doing quite well into Ireland ATM, about S9!
0425 Petshop Boys 'Its A Sin'
I'm out.  Thanks for the tunes, hope to hear you again soon!

Thanks for the show!

+-RH

72

Equipment / Re: Who here doesn't have a MFJ ATU?

« on: May 26, 2022, 1515 UTC »

I've always used properly tuned antennas for my stuff and don't use tuners with one exception.  For a while, I had a FT-857 in my pickup with a CB whip on the back.  I had an SGC autotuner in the bed feeding the whip.  It worked pretty well on 40 and 20, not real good on 75M though.

+-RH

73

General Radio Discussion / Re: Becker bill to remove police radio encryption picks up support

« on: May 20, 2022, 2308 UTC »

Regardless, I fully support this.  I shouldn't have to own a $3K radio and have a buddy get me keys just to hear how my tax dollars are being wasted.  Anything to promote government accountability I'm in favor of.

+-RH

74

Huh? / Re: Why is there so little interest in MW pirates?

« on: May 20, 2022, 1733 UTC »

The other thing is that not that many people today have the real estate to string up a +100ft antenna.

^THIS!


~275' for an AM half-wave dipole at the top of the MW BCB band, and for most realistic deployments, a horizontal MW antenna is going to be so low as to encounter significant ground losses along with largely being a cloud warmer with what power it does radiate upwards.

There is the vertical route, but that also typically means serious loading to get a reasonably workable deployment, plus it is also dealing with ground losses unless deploying numerous ground radials or quarter-wave tuned elevated radials. Elevated radials can be loaded as well, but that typically incurs even further losses.

Now factor in the typical MW noise floor these days, plus how many even general radio enthusiasts have truly decent MW antennas optimized for weak-signal reception these days?


It is akin to an amateur doing 160m mobile. Even with a few hundred watts into an extremely-loaded vertical, the often resulting QRPp experience can be an exercise in patience.... or frustration, and that is on an band with (hopefully) other active participants having (again, hopefully) decent antennas for receiving.

Yup, that's pretty much my experience.  That said, a 50' vertical with 8 140' radials works OK on 1720KHz or so with reasonable performance.  If you want to throw power at it though the loading coil will have to be very large.  The numbers I ran found that such a setup can expect close to 20A of base current with 1KW on the input!

Even the places I like to use have barely enough room for an antenna that size.

+-RH

75

Amateur Radio / Re: Dayton Hamvention

« on: May 20, 2022, 1722 UTC »

Prior to the kung-flu myself and the OP would make the journey every year.  Dayton had its charms, and yes, I was there for 'Crapapocalypse'.  Some of the key pieces of the station came from there, including both my previous linear amps.  Xenia is a nice venue, sans the stench of a thousand horses from the stables.  The down side is unlike Dayton, most of the flea market is on grass.  If (when) it rains, it's mud city.  Speaking of which the weather is always unpredictable.  I've seen wind, sun, thunder, and sleet over the last decade.

I wish I was there.  Fun stuff to look at, but with the price of gas and the work schedule what it is, I just couldn't make it this year.  Maybe next one.

+-RH