Part #15 gear out there.

[ThaDood]

(Yeah, this was moved from RF Workbench.) Lots of home brew radiating gear, (For the 10ft FCC Part #5 compliant stuff.), but you have companies like, www.sstran.com , www.chezradio.com , www.am1000rangemaster.com , www.theradiosource.com , www.pll.gr , www.vectronics.com , www.iamradio.net , and there's others out there. Some companies even got-in on doing the 10ft Part #15 antenna like, www.isotronantennas.com , (Tell them that you want Part #15 compliant. Not cheap, but....) So, there's stuff out there. And, anything that's Carrier-Current, (Where you permissibly couple to the power lines.), from LPB, Inc., and Radio Systems, gets bought out almost immediately from ebay. So, somebody wants that gear.

[ChrisSmolinski]

Talking House transmitters turn up at Goodwill now and then, I found three of them new in box last year.

[Rob.]

I'm looking for an inexpensive carrier coupler for a low power AM TX I have. Yes, they do get gobbled up on eBay quickly.

I run a whole house/yard FM TX that broadcasts anything I am listening to on my computer... including my KiwiSDR so I can listen remotely in the yard.

[ChrisSmolinski]

I run a whole house/yard FM TX that broadcasts anything I am listening to on my computer... including my KiwiSDR so I can listen remotely in the yard.

I do something similar now and then, I use one of the inexpensive car FM transmitters designed to broadcast your iDevice audio into your car radio:

https://www.amazon.com/gp/product/B001AIM5ZE/ref=ppx_yo_dt_b_search_asin_title?tag=blackcatsyste-20

BTW these devices all use the same IC to do the transmitting. It's a neat chip, it has an I2C interface, you can actually override what the little uC in the dongle sends to it, and set your own frequency and other settings, and send RDS data as well.

[ThaDood]

Oh boy... On a Carrier-Current Coupler, you may have to roll your own, since LPB and Radio Systems are gone. However, there are power line couplers for mining companies, (At least, there use to be.). That was the only way that they could send down a radiating signal into a mine shaft was to couple to the power lines going down there. With all of these mining companies going bye-bye, I'll bet one can be had. Ernest Wilson, formally of Panaxis Productions, had shown in is Carrier-Current books on how to build a coupler. Also, look for on-line .PDF books by James R. Cunningham for this to download. Basically, you are looking for a medium wave tuning network that let's you tune down to very low impedance, like 10 Ohms and less. Over 20 years ago, JTA gave me a Radio Systems TR-20 transmitter and a CP-15 coupler. The problem was, it looked like lightning directly hit it. The TR-20 was a total loss, with thumb sized burnt holes in both the PS and Finals boards, but the CP-15 Coupler was fixable, and I'm using that today. So, ya never know. 

[ThaDood]

Here's a radio Systems CP-15 Carrier-Current Coupler on ebay now,   https://www.ebay.com/itm/RADIO-SYSTEMS-PHASE-II-CP-15-COUPLER-AM-RADIO-BROADCAST-TRANSMITTER/184186421837?hash=item2ae25dc24d:g:Vy0AAOSwr9ReVYyS

[JimIO]

You could start with this to make one:

https://www.ebay.com/itm/DIY-Kit-QRP-manual-Antenna-Tuner-Tune-1-30Mhz-For-HAM-RADIO-CW/182607192047?epid=23005640968&hash=item2a843c9fef:g:O~AAAOSwgkRVT0hS

~

[ThaDood]

Huh... Might be OK to Neutral-Inject in to the Neutral of the home AC power, but I certainly wouldn't couple that to the HOT. Heck, for the price, you can't beat it. And, since it's a kit form, most likely you can improve it to work much more efficiently on the AM BC band. That 1MHz limit is a bit FREQ limiting, since most Carrier-Current ops use the lower part of the band, since the lower FREQ's can ride the long power lines further. 

[JimIO]

Just add a couple AC rated capacitors and fuses and you could feed both sides.

~

[JimIO]

https://components101.com/capacitors/x-rated-or-dropping-capacitors

~

[Azimuth Coordinator]

I have in the Rack a very Rare Broadcast Warehouse TX1  10mw  FM Exciter.. That is part 15 Compliant.. But depending on the Antenna..  you can easily exceed 250uv @ 3 meters.. My Singer NM 37/57  has it a 500uv @ 3 meters with a Circular Polarized Antenna.  It's been my main On Air for several years..  Range is around 1000 feet with good fm tuner around 200 feet with your average portable radio.   I started with a Ramsey FM100B which was pretty good for the price.  But then the next thing you know there's a PTEK FM25E in the rack... 

tAC

[Rob.]

I have a Drake FM-1000 CATV stereo modulator that I use for around the yard broadcasts. It has a crippled antenna so it stays within the confines of Part 15. Nice audio out of it.

[chanito]

What I need is an accurate VHF QRP SWR/Wattmeter. I've been using a Diamond, but down to the 1 watt range I don't think it's very accurate. Need to be able to measure down to mw.

[secretlab]

I recently bought a ChezRadio Procaster AM system out of Canada. This is the lower cost alternative to the US made Rangemaster. It includes a one-chip audio processor which is serviceable but not very loud. External processing may be used instead.

Having also owned a Rangemaster, I find the Procaster's coverage is less in either a strictly compliant § 15.219 ground mount or a 10' elevated mount ('shielded' ground - center conductor of 7/8" Heliax to ground with shield grounded at bottom but open at the top). It does sound like a local within 1000' though, which was the goal. Build quality of the Procaster is very good. Audio quality is OK. Gerry of Chezradio was helpful with a minor issue but seemed unwilling to discuss technical aspects of his proprietary system.

in an elevated installation, what constitutes a suitable RF ground point is in the judgment of any FCC agent who may come to inspect your transmitter. A certain FCC NOUO (Notice of Unlicensed Operation) has seemed to indicate that a 'shielded' lead or path to ground may be acceptible. Here's the underlying rule:

§ 15.219 Operation in the band 510-1705 kHz.
(a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed 100 milliwatts.

(b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters.

[Josh]

(b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters.


"that's no 50ft ground lead, that's the dc return to the psu"