diy transmitter?

Status
Not open for further replies.

kb2vxa

Completely Banned for the Greater Good
Banned
Joined
Mar 22, 2005
Messages
6,100
Location
Point Pleasant Beach, N.J.
Hi Clam and all,

Let's not try to out tech each other, OK? All I'm saying is a noob is ill prepared to jump in the deep end with both feet.

"All components are not soic surface mount, but even so you needn't look any further than inside your scanner for a good digital frequency synthesizer. That same circuit could be used as part of a transmitter."

All well and good but you were talking about a synthisized all mode transmitter so by the time you're done with all that you'll need something a little bigger than an Altoids tin to put it in even using multi layered PCBs and SMT components. Frankly I wouldn't even try working with them using my Weller soldering station and can't be bothered with hot air reflow. That brings us to the simple tools department where I'll leave off.

"'ve been on amateur bands but not for some time. Never did CW."

OK, you gave the impression that Amateur Radio was foreign to you.

"I hold none of those degrees and have designed such circuits."

Same here but I was making a point about a certain level of knowledge by way of comparison.

"I too have worked in the electronics and broadcast industries for over 30 years."

I've not worked in broadcasting directly but I worked for Datatek (Grass Valley's prime competitor) building switching systems and others for TV Master Control. I was in on the ground floor of the development of the digital signaling that rides in the vertical interval and MTS stereo, quite an adventure. Now it's all digital, NTSC bye bye.

There you go, we're a couple of tinkerers in a degreed world proving that work experience and a lot of time with nose in book can build a satisfying career. And just think, I started out by sticking a bunch of flashlight bulbs, switches and batteries in a cardboard box when I was about 7 years old. Hey, if I knew binary I would have been years ahead of Altair! (;->)

"It certainly didn't help that several of the original posts in this thread were people scaring him, telling him the legalities and reasons not to do it."

Quite. They had the right idea at least on one side of the coin, unless you know the rules of the road don't drive. The practical approach is learn the rules and apply for a license TO drive be it a ham license or nothing more than a knowledge license. BTW, back in the 60s my friends and I ran a pirate radio station and got busted eventually. We only got a cease and desist order but today the FCC isn't so generous.

Oh, I built the transmitter right out of the pages of the Radio Amateur Handbook, thank you ARRL! (;->)
 

gmclam

Member
Premium Subscriber
Joined
Sep 15, 2006
Messages
6,453
Location
Fair Oaks, CA
slidder said:
hey all,
i was just curious as to how i would go about making a low powered transmitter, <1 watt, at a frequency of my choice . and also have the ability to change the frequency?
The OP here asks how to "make" a transmitter and does not address where the design will come from, how the thing will be tested or aligned. He doesn't mention what he intends to use it for, so we don't even know what type of modulation it should use. I never suggested building a unit capable of all modulation types, but meant that one type of many could be selected.

Nowhere in my posts did I mention anything about a design that has to fit in an Altoids can. For all I care this thing could be the size of a desktop PC. The OP does want to be able to change the frequency, so I suggest using a digital synthesizer. Certainly modern circuits are surface mount and on multi-layer PCBs, but there are plenty of parts in larger packages still available out there.

I've been building electronics stuff since I was in single digit years. I've designed and co-designed patented products used in many homes. My work in (TV) broadcasting started with Ampex Quadraplex VTRs, switching master control, ... to (recent) technical director of several hours of continuous live television (using Grass Valley switchers). But my work in TV runs the gamut from set building (over 30 years ago) to producer/director/editor (linear 1" editing and NLE) and most jobs in between.

But back on topic .. if the OP was just looking for some parts he could "throw together" and start emitting RF into the atmosphere, then perhaps it was a good thing he was scared off. If he "needs" such a device, I hope he will purchase one already commercially available. If he's interested in this topic as a hobby or profession, then certainly education is the key. As N_Jay pointed out, AARL is one good source.
 

slicerwizard

Member
Joined
Sep 19, 2002
Messages
7,768
Location
Toronto, Ontario
slidder said:
lets say i want a uhf range, and do not want it to be strong enough to go any further than the area of my house and land(not that large) it would be audios i suppose, but i guess video would be something i could look at later. not operating under anything as the frequency would be "under the radar" sort of speak.
i jsut want to lnow how i can for instance, send out 888.8877 mhz fm and be able to recieve it on the other side of my house with a scanner.. .. REAL basic right now i jsut want to under stand how tranmitting works at very LOW power range
I wouldn't call the 890 MHz range "UHF" and I really don't see you building a ~900 MHz transmitter anyway. Never mind the fact that you're not licensed for any of these frequencies you plan to walk all over.

Get yourself a baby monitor, cordless microphone or an FRS radio and play with the channel buttons. Problem solved.
 

slidder

Member
Joined
Aug 16, 2007
Messages
72
Location
Georgtown
slicerwizard said:
I wouldn't call the 890 MHz range "UHF" and I really don't see you building a ~900 MHz transmitter anyway. Never mind the fact that you're not licensed for any of these frequencies you plan to walk all over.

Get yourself a baby monitor, cordless microphone or an FRS radio and play with the channel buttons. Problem solved.

who said anything about 890???
any ways i have to agree, some of you guys are trying to out tech each other. and yes i really didnt give alot of info but at the same time you jsut assumed i am some noob that has NO electronics experience..
and half of you didn't read my posts fully .. what i am after is how to build a transmitter that i am capable of changing the frequencies dynamically . i have an abundance of tools i just need to know what parts to get . end of story.. i don't se why i should go on an explain my knowledge of electronics to get a certain level of respsonse.. however some of the responses were quite comical
 

slicerwizard

Member
Joined
Sep 19, 2002
Messages
7,768
Location
Toronto, Ontario
slidder said:
who said anything about 890???
Some guy who wrote "i jsut want to lnow how i can for instance, send out 888.8877 mhz fm". Who was that?


and yes i really didnt give alot of info
And you still haven't.


but at the same time you jsut assumed i am some noob that has NO electronics experience..
You have not exhibited any RF experience.


and half of you didn't read my posts fully .. what i am after is how to build a transmitter that i am capable of changing the frequencies dynamically
Oh don't worry - we read them thoroughly. Y'see, the problem is - you don't give any useful information. You want to change the frequencies dynamically through what range of frequencies?? 1 MHz to 1 GHz? (I get the impression that you're expecting to do just that) The fact that you don't consider this to be a critical parameter required to answer your question just shows that you have no idea what you're getting in to.


i have an abundance of tools i just need to know what parts to get . end of story.. i don't se why i should go on an explain my knowledge of electronics to get a certain level of respsonse.. however some of the responses were quite comical
You wrote that you want to monitor these transmissions on your scanner, so that means they have to be at least what, 25 or 30 MHz? You even mentioned ~890 MHz - do you have any idea of the tolerances involved in building a transmitter circuit that can oscillate at such frequencies? Apparently not.

You want to build it and you want to know what parts to get? If anything, you'll be getting a kit. I'm sure you could've searched the Internet a few times by now for something like "RF transmitter kit". I'm sure you don't expect us to do it for you, since you haven't provided any specs.
 
N

N_Jay

Guest
slidder said:
who said anything about 890???
any ways i have to agree, some of you guys are trying to out tech each other. and yes i really didnt give alot of info but at the same time you jsut assumed i am some noob that has NO electronics experience..
and half of you didn't read my posts fully .. what i am after is how to build a transmitter that i am capable of changing the frequencies dynamically . i have an abundance of tools i just need to know what parts to get . end of story.. i don't se why i should go on an explain my knowledge of electronics to get a certain level of respsonse.. however some of the responses were quite comical
And so is this post!:lol: :evil:

You obviously did not read (or did not understand) many of the posts in this thread.
You have added one new requirement (capable of changing the frequencies dynamically), while answering none of the fundamental questions.

So what you have shown is that you are a NOOB, you just don't know it! Making you the worst kind)
 

hoser147

Member
Joined
Dec 17, 2005
Messages
4,449
Location
Grand Lake St. Marys Ohio
No sense in everybody tryn to out tech each other or advise about FCC fines and Jail or what not.....Its just a simple question about a DIY transmitter. They are everywhere in peoples lives. IE the garage door opener, TV remotes, Wireless Intercoms, and gaming controllers. The OP is not trying to rebuilt the electronics world hes just asking a simple DIY question. A simple answer would suffice..No need to make a Mountain out of a Molehill.............H:wink:ser
 

gmclam

Member
Premium Subscriber
Joined
Sep 15, 2006
Messages
6,453
Location
Fair Oaks, CA
FRS radios for $49?

gcgrotz said:
UHF = 300 to 1000 Mhz

Build a kit, you will learn from it.
Actually UHF is 300 MHz to 3000 MHz.

I think the idea of the OP getting a FRS radio is a great idea. They usually come in pairs, so one could be taken apart and "examined" (perhaps some learning will take place) while the other used to transmit from one side of the house to the scanner on the other side.
 

slicerwizard

Member
Joined
Sep 19, 2002
Messages
7,768
Location
Toronto, Ontario
hoser147 said:
Its just a simple question about a DIY transmitter. They are everywhere in peoples lives. IE the garage door opener, TV remotes, Wireless Intercoms, and gaming controllers.
None of those are DIY transmitters.
 

kb2vxa

Completely Banned for the Greater Good
Banned
Joined
Mar 22, 2005
Messages
6,100
Location
Point Pleasant Beach, N.J.
"No sense in everybody tryn to out tech each other or advise about FCC fines and Jail or what not."

That's why my head Hertz.
 

zz0468

QRT
Banned
Joined
Feb 6, 2007
Messages
6,034
This thread is really pretty funny, between the vague request on how to build a transmitter, to the overcomplicated answers. But we never really did get to the bottom of just what the OP wanted to do beyond receiving something on the other side of the house with a scanner and being able to change frequencies.

To the OP:
Have you considered just getting a signal generator? You should be able to hear that across the house. If you just "want to under stand how transmitting works" (your words), you'd be better served cracking a few books first. Then, come back and tell us what you really have in mind and all the best and brightest minds at RR can point you in the right direction.
 

slicerwizard

Member
Joined
Sep 19, 2002
Messages
7,768
Location
Toronto, Ontario

DickH

Member
Joined
Mar 12, 2004
Messages
4,067
N_Jay said:
So what you have shown is that you are a NOOB, you just don't know it! Making you the worst kind)

50 years ago, if he walked into the shop, we would have placed him in the category of "He knows just enough to be dangerous". :)
 

kb2vxa

Completely Banned for the Greater Good
Banned
Joined
Mar 22, 2005
Messages
6,100
Location
Point Pleasant Beach, N.J.
Am I on the right web site or did some hacker put a redirect on the server and I'm on QRZ?

Now my Heinrich Hertz!

Oh, in case you haven't noticed he headed for the hills some time ago. I think I'll join him but first I need a Vicaden... that is unless you have something more to entertain me with.
 
Status
Not open for further replies.
Top