Messages

436

Equipment / Re: Test Equipment for First Time Build

« on: September 10, 2019, 1937 UTC »

I picked up a MSO2202A last year.  It replaced an old 60 MHz dual channel Tek whose trace had become so dim it was almost impossible to make out.  I do prefer a conventional scope for a lot of things (looking at things in XY mode) but it's hard to beat the portability and price v. feature set.

+-RH

437

Equipment / Re: Test Equipment for First Time Build

« on: September 10, 2019, 1726 UTC »

A scope is mandatory, I'll second that.  Garden variety scope probes are good to about 100W or so.  I've burned out several probes over the years at the 500W level, even though the signal voltage fell within the rating of the probes.

I would also highly recommend a good soldering iron and quality solder.  My main station is a Hakko FX888D and I run Kester 63/37 mild flux solder.  This is the equipment I do rework with as well to pay the bills.  For small one off's I'll spin my own boards in the kitchen using a photo etch process using pre-sensitized boards.

+-RH

438

General Radio Discussion / Re: Swiss To Shut Down FM

« on: September 09, 2019, 1722 UTC »

DAB over there runs in the ~175 MHz range, what we used to call VHF high or band III.

+-RH

439

General Radio Discussion / Re: Washington State Ham Group Tracks Interference

« on: September 07, 2019, 1744 UTC »

When working for a radio station 15 or so years ago, I did similar.  Our RPU system in the 450 band was receiving interference.  It looked like some rogue signal sweeping through the band.  We traced it to a malfunctioning paging transmitter 7 miles away from our receive site.  The owners were contacted and had it fixed within a week.

+-RH

440

General Radio Discussion / Re: Radio Romania International no more on shortwave

« on: September 05, 2019, 2348 UTC »

FWIW, a lot of that is on Galaxy 19, TVR, TRT, et all.  There are some music channels up there in the clear as well.

+-RH

441

The RF Workbench / Re: I need some help writing some arduino code for RS232

« on: September 04, 2019, 2346 UTC »

People have done that, search 'arduino ad9850'.
If you want to start from scratch search 'arduino serial.begin(9600)'.

I've been down that road many times and have not found anything close to what I'm looking for.  If your so sure its out there, you could bring a link.

+-RH

442

The RF Workbench / I need some help writing some arduino code for RS232

« on: September 04, 2019, 2100 UTC »

This could very well become a community project.  See related video here https://youtu.be/EwMDEjv1Hfc  I have built a DDS based VFO, but need some way to control it once embedded in the bowls of various pieces of equipment.  The basic idea is this; the project listens to an RS232 port for valid commands.  if it receives something like "f=6925<CR>" the VFO output frequency is set to 6925 KHz and echos "f=6925<CR>".  It would also be nice if other commands like "RF ON", "RF OFF" and "f+5", +10, etc could be implemented.

I've looked all over and haven't really found anything like what I need.  The biggest problem seems to be how to get the serial data into a string, and then begin processing it once it detects a carriage return.  if/then/else statements could then be used to carry out the desired functions.

Thanks in advance,

+-RH

443

The RF Workbench / Re: Class D output match

« on: September 03, 2019, 1622 UTC »

First off, what turns ratio are you needing? Everything I build is 1:1 ratio to keep modulator current levels in sane territory.  I also recently changed the output topology in my transmitter to a coaxial wound binocular type core.  It does get warm at 750 watts carrier, but not hot.  I needed an isolated output in the PA stages to facilitate line derived B+ in the following generations of the transmitter.

FWIW, binocular type output transformers are the standard in solid state PA's from DC to 200 MHz.

+-RH

444

North American Shortwave Pirate / Re: Mix Radio Int. 6880 USB 2255 utc 30 Aug 2019

« on: August 30, 2019, 2314 UTC »

6880 KHz 20190830 2312z sounding pretty good here with some rolling fades.  Micheal Alan 'Morning in Tunisia' according to shazam.  an official S9 here.
2315 Kirk Whalum 'Goin In Circles'  Nice smooth bass
2337 MRI ID, into Cutting Crew remix.

How about some 'Johnny Hates Jazz' 
Thanks Mix for the 'Shattered Dreams'!
Rattling the walls here with some Depeche remix action @ 2349!
0002 Grimes 'We Appreciate Power' Cool!
0008 MRI ID, into SOAK 'Everybody Loves You'
Gotta run out for a bit, but I have the tape rolling, I'll send you an aircheck later tonight.

0106 Phil Collins 'In The Air Tonight' remix
0117 -off air-



Thanks for the show!

+-RH

445

General Radio Discussion / Re: FCC petitioned to open up 45 to 50 MHz for DRM+ broadcasts in the USA

« on: August 30, 2019, 0401 UTC »

You may wind up with the FMeXtra thing all over again.  DRM+ receivers are available, but not in those frequencies ranges.

+-RH

446

Huh? / Re: eevblog guy on the Tesla Solarcity roof fires at 7 Walmart stores

« on: August 29, 2019, 1721 UTC »

All the more reason to have a concrete roof.

+-RH

447

Huh? / Re: eevblog guy on the Tesla Solarcity roof fires at 7 Walmart stores

« on: August 22, 2019, 1833 UTC »

I saw that this morning in my feeds.  He's been doing a lot of other solar roadway failure videos lately.  He also had a meterorite take out one of his rooftop LG panels as well.

+-RH

448

For Sale / Wanted / Barter / Re: Looking for AM broadcast monitor/processor

« on: August 22, 2019, 0205 UTC »

Are you looking for something tunable only, or wideband?  As far as monitor are concerned, the analog Belars are OK, (AMM-1, -2, -3), and are good to 30 MHz.  The AM wizard was probably the best one they made (AMMA-1), also good to 30 MHz.  The Inovonics ones are AM band only, usually only to 1710 KHz, models 520, and 525 were adequate.  TFT made some wideband ones as well, but documentation is spotty and with the company gone now, if you need a book, your on your own.  Older Harris monitors were cool, I like the AM-90 the best.  It had a cool plasma display.

The Belars pop up on ebay from time to time, and at hamfests.  Be prepared to do some rework on them.

If you want to go analog processing, CRL's are fairly common.  I have two Amigo AM's as backup units to my stereo tool setup.  The inovonics processors weren't that bad, although the clippers in them were not filtered, so you can't really push them that hard before they get grungy.  The CRL's are the same way.  Top shelf is probably the 9100A (B was the stereo version with the right cards), although most of them are over 30 years old and will need some love.  They can be a devil to get running again as some of the VCA's you cant get anymore.

+-RH

449

Bacon, BBQ, Beef, And More / Re: Meat consumption needs to be cut to save the planet? Follow The Money

« on: August 21, 2019, 1514 UTC »

In my short time on this planet I have learned that anytime some organization tells me something is good for the planet, it really means its good for their pocket.  I'm not suggesting that environmental stewardship is a bad thing, or unnecessary, but people do tend to go to the extremes, especially when financial lubrication is involved.

"The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary." - H. L. Mencken

+-RH

450

Amateur Radio / Re: Huntsville Hamfest 2019

« on: August 11, 2019, 2052 UTC »

If they had one I would consider it!

+-RH