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Technical Topics => Equipment => Topic started by: ThaDood on June 02, 2018, 1536 UTC

Title: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 02, 2018, 1536 UTC
Yeah!!!!! Finally!!! A Part #15 AM Stereo C-QUAM kit!      https://radiojayallen.com/cuthbert-am-stereo-c-quam-transmitter/    Question is, will this be a come 'n go sort of thing, or will it be a neat Part #15 buzz that can help give LPAM and C-QUAM stereo a kick where it needs it? Time will tell. The sad part is that it may end up being that there will be more AM stereo transmitters than receivers out there. However, there are kits out there for converting you favorite stereo tuner, or receiver, to have C-QUAM ability, like this site,     http://meduci.com/   
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: Josh on June 02, 2018, 1609 UTC
It'd be nice if the sdr app makers would add am stereo to their repertoire.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 02, 2018, 1647 UTC
Yeah, no kidding! Just how hard would it be to write up software for SDR's to be able to have C-QUAM capabilities? I am the last person to know this since I almost failed out of computer electronics in college, since I hated machine language.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ChrisSmolinski on June 02, 2018, 1745 UTC
It'd be nice if the sdr app makers would add am stereo to their repertoire.

SdrDx decodes C-QUAM.  http://fyngyrz.com/?p=915
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 02, 2018, 1937 UTC
Good to know about the SdrDx! Hmmmmmmm, Radio Jay didn't mention the actual ebay site for the Cuthbert C-QUAM TX kit, so here that is,      https://www.ebay.com/itm/AM-Stereo-C-QUAM-Transmitter-Kit/132644744317?hash=item1ee23e2c7d:g:U5gAAOSwIgNXoPEJ      and the quick demo Youtube VID,     https://www.youtube.com/watch?v=NEDBxmDJYwo&t=6s       Neat item, but it is nice to know where to get it. Just my $0.02 worth.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: Stretchyman on June 02, 2018, 2000 UTC
Why's is it on VEROBOARD?

Why not on a PCB?

?
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: TheRelayStation on June 02, 2018, 2008 UTC
It'd be nice if the sdr app makers would add am stereo to their repertoire.

SdrDx decodes C-QUAM.  http://fyngyrz.com/?p=915
so does SodiraSDR which i prefer since it has many adjustment capabilities for the advanced user, it also has DRM decoding.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ChrisSmolinski on June 02, 2018, 2229 UTC
Why's is it on VEROBOARD?

Why not on a PCB?

?

Yes, I was thinking the same thing. $169 and its on prototyping board, not a proper PCB? You have got to be kidding me. 
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 03, 2018, 0342 UTC
Eh, who knows??? Maybe he's gotten veroboard boards for a dime a dozen. I can't bitch, I've built my 22M mW transmitter on one as well. Certainly doable. Still, the kit is under $200.00, so Cuthbert's broken that ceiling barrier for a kit like this. I seem to recall paying almost that much for a Panaxis AM-100 100mW mono exciter kit back in 1991. (I still have that.)
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: Stretchyman on June 03, 2018, 1007 UTC
PCBs are $1 sq inch double sided from OSHPARK in quantity and even if that's too expensive, China will probably do it for much less.

There's some no excuse using Vero for anything these days, it's crap and always has been, even smells funny, never a good sign!

Seriously tho' ANY kit should be on a PCB.

Maybe the 'Designer' has never laid out one before?

Time to learn I think...

Well done on the price, if that's what you want.

No need for anything like this other than US??

Stereo on SW?....Hmmm......
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: redhat on June 03, 2018, 1010 UTC
Stereo on SW?....Hmmm......

I've been doing it for years ;)

+-RH
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: Josh on June 03, 2018, 1637 UTC
It'd be nice if the sdr app makers would add am stereo to their repertoire.

SdrDx decodes C-QUAM.  http://fyngyrz.com/?p=915
so does SodiraSDR which i prefer since it has many adjustment capabilities for the advanced user, it also has DRM decoding.

Awesome, already got sodira installed. However, it's a huge cpu hog, wonder what's going on there.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: TheRelayStation on June 03, 2018, 1814 UTC
It'd be nice if the sdr app makers would add am stereo to their repertoire.

SdrDx decodes C-QUAM.  http://fyngyrz.com/?p=915
so does SodiraSDR which i prefer since it has many adjustment capabilities for the advanced user, it also has DRM decoding.

Awesome, already got sodira installed. However, it's a huge cpu hog, wonder what's going on there.
not sure but i dont have that issue.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: JimIO on June 05, 2018, 0445 UTC
DRM is dead. What is needed is an open source digital format for MW and SW.
As for part 15 AM don't you need to put the transmitter at the junction of your ground radials and 3 meter vertical? That is "outdoors". I would not pay that kind of money then put that thing outdoors.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 05, 2018, 1531 UTC
Ahhhhhhh, but that's where you can be creative here. My AM1620 transmitter is just mounting in the garage, on the inside "A" point of the eves. The radiating antenna is about 12 inches short of 3 Meters in length, to compensate to feeding a 12 inch #8AWG from transmitter to the actual radiator, thus making it Part #15 FCC compliant. You may have other locations that can work, like the inside / outside eves of a tool shed. Passing thought, again... Not everyone can do this, (Including me, thus why I garaged-it.), but your house attic eves can be utilized the same, if you own your own house. 
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: JimIO on June 05, 2018, 1620 UTC
I'm a big fan of creativity. What is your ground system and  usfull range? Now that the nice weather is here I would like to try something. You can generate 800 or 1600 Khz with a $4 Aduino uno clone and use a $1.25 MP3 module as audio source/modulator.
Waiting on ebay for TC4420 i.c.'s for class D output.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: ThaDood on June 05, 2018, 1838 UTC
The AM1620 side is the Radio Systems, I Am Radio, (Updated Talking House.), and the ATU (Antenna Tuning Unit.), is mounted up at the eves. I bought the thing in 2010 when it was around $400.00 at the time. The actual TX is pumping out the massive 92mW PEP from a floor rack. The GND'ing? Old outer braid RG-8 coax to an 8ft GND rod. No array below. (The manual actually tells you to ground for lightning protection.) I added a Gas Discharge Tube to aid in protection. (Albeit, I know that it will not take a direct hit, but what will?) Heck, see it all for yourself,      https://vk.com/realfreeradio      (I purposely do not use facebook and Twitter, and 4 years ago Just-In Timberlake wiped everyone's myspace. So, VK.) Anyway, the top has the PIC's of a ragtag studios, the carrier-current station AM610, the rack with the AM1620 TX, then the ATU, and the newer AM1620 copper 9ft antenna. Range? Varies, a lot. Winter time I've heard it in a parking lot over 3 miles away, albeit any noise would obliterate it. The good range towards the northern field (Very clear.) is heard over a mile driving, in the day. In November 2017, the CB whip was swapped for the 5/8th" copper pipe, with capacitive Tophat. Boomer calculated that my range could be +6% better, and I think he's right on the money. (Will the listeners notice? Doubt it.) Nighttime? Maybe 1/2 a mile over Cuba and South Bend, IN stations. (BTW, AM610 feeds audio to AM1620 in the garage.) How does it all work? Most of the time, very reliably. However, as you can see from my PIC, not the neatest installations. (Just like a real AM station!) However, PIC's of other Part #15 stations on ALPB and Part15.us sites put me to shame, but will AM C-QUAM stereo be in my future? Lookin' at it!
Title: Re: And, Cuthbert 6 Channel 3 Band Stereo Audio Compressor!
Post by: ThaDood on June 08, 2018, 1754 UTC
A mini Optimod from Cuthbert,     https://radiojayallen.com/cuthbert-6-channel-3-band-stereo-audio-compressor/        I certainly hope that it is light years better than Ramsey's Stereo Companion. That thing just sucked to high heaven with terrible S/N Ratio. From the sounds of it, this should be much better, and it's an all-in-one. I use three steps of processing currently. From the boards, to an original TERK VR-1, (Not the Audiovox version.), then an Alesis compressor (Set at 4:1 radio.), then an added 16 band EQ. The EQ was actually added to reduce harsh S's and T's from podcasts that don't use a DeEsser unit. It all works, but all-in-one package is very tempting.
Title: Re: Cuthbert AM Stereo C-Quam TX Kit! Finally!!!!! Boomer's AM Stereo Demos Page
Post by: ThaDood on June 09, 2018, 2113 UTC
Yeah, me again... Geeeeeeeeeeeez, if only Motorola did 1/2 as well as Boomer did in demoing AM stereo,     http://boomerthedog.com/am-stereo-is-cool.html     Enjoy!!!! (That Carver receiver is to die for.)
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! It's here!!! Now to build, test,
Post by: ThaDood on July 21, 2018, 1852 UTC
       COOL!!!! Sean's C-QUAM kit came in. And, what little time I've had to check it out, it's put together very cleverly. The PIC instructions are much the way that assembly procedures were when I went to work for that RF Plasma Generator / MRI Generator company MKS Instruments back in 2006. I did change over the .BMP's to .JPG's. Ubuntu seemed to handle that better. The PIC's are defined high enough for really big blow-ups of close views. All in all, it appears very doable, indeed.
       The plan? Build the kit the way that Sean has it, test with the 3M wire antenna on the 3rd FREQ, like 1650kHz, then implement the FREQ safety change and EXT ANT MOD's. And then, after extensive testing, swap out the I Am Radio TX for the Cuthbert TX on AM1620. That's the plan, anyway. Then? See what can be done to have AM Carrier-Current, AM610, to go stereo. I do see that Sean has it so that the kit can go either 100mW, USA Part #15 allowable with the 10ft antenna, or 400mW, which would be fine going Carrier-Current operation. Now, to get time to build and test.


Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: OgreVorbis on July 22, 2018, 0844 UTC
Yeah, no kidding! Just how hard would it be to write up software for SDR's to be able to have C-QUAM capabilities? I am the last person to know this since I almost failed out of computer electronics in college, since I hated machine language.

For near the same price as this you could get a HackRF. With that, you can pretty much modulate any type of signal you want. Sure you could do c-quam with it, but I don't know how. It doesn't require assembly language programming. It uses the gnuradio software which is like a flow chart. Not sure how well it works on AM band though. Some say it works down to 10 MHz and others say 1 MHz.
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!! On-Air performance.
Post by: ThaDood on August 18, 2018, 1659 UTC
Well, late in July I was able to power up the Cuthbert Transmitter and get RF out. The whole RF stage is built either Class D, or E, and for a very high impedance, which is expected for a 10ft wire antenna on MW. Unfortunately, I have very little audio pumping out of it, and the O'scope confirmed (As did my ears.), that practically nothing was coming out of the audio IC, a TDA7284 ALC chip. (You probably have one in an 80's boombox, or even a stereo VCR, that has audio leveling for recording, instead of manual adjustment.) Boomer, of Carrier-Current station AM690, was doing fine with his Cuthbert TX, so I suspected that I had a bad audio IC. So, I really didn't need it, and just bypassed it all together, since I have managed audio feeding it anyway. WOW!!! Even on a low key AM stereo walkman, what a difference from AM mono to AM stereo! As far as stereo separation? Mine is about that of an early BA1404'ed Ramsey FM-10 from 1989, but better AF response. (I've had several of those Ramsey FM-10's over the years from the original to model C.) Testing on 1580kHz from the indoor wire antenna. Even on a mono receiver, that audio has more punch to its quality. And from the indoor wire antenna, on a car stereo, range MAX's out to just over 1/4 mile. Still, for what it is, if you don't have AM Stereo around where you live, it's still a way for you to provide AM Stereo to leftover receivers that you have with that capability. I do see that AM Stations are starting to dump HD Radio for C-QUAM Stereo again. Buffalo, NY's WWKB 1520AM just turned their AM Stereo back on again. Too bad that's sports talk. The next step? I've just bought two Meduci C-QUAM boards for $28.00USD each. Having just a couple of 1990's low scale AM Stereo walkmans just doesn't cut it, so I plan to roll my own AM Stereo receivers via modifications. https://www.ebay.com/itm/163031984400
Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!!
Post by: Tim Bucknall on September 01, 2018, 1755 UTC

No need for anything like this other than US??

Stereo on SW?....Hmmm......

if he does a constructed version that can be run right out of the box i'll bite for sure. just throwing it out there in case Cuthbert is reading this :-)


Title: Re: Cuthbert AM Stereo C-Quam Transmitter Kit! Finally!!!!! Open source now?
Post by: ThaDood on October 17, 2018, 1925 UTC
          It's been mentioned to me that the other reason that Motorola C-QUAM AM Stereo is getting a push at the hobby level is that the patents for that have expired, thus in today's terms, C-QUAM could be considered Open Source with only yours, and today's tech, being the only limits for applications. Yet, another passing thought, but a good point that I thought was pointed out to me.