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Technical Topics => Equipment => Topic started by: Telegrapher on March 20, 2019, 1847 UTC

Title: Questions CB and TX base station project
Post by: Telegrapher on March 20, 2019, 1847 UTC
Hi,

I am planning on building a base station at home for basic TX experiments. Starting with CB.

I currently have a CB antenna hooked up to a magnet mount attached to a aluminum plate from a disassembled pc case. With an additional wire of copper going from the antenna to one of the water pipes that are used for the heating temperature in the room.

I need to build a tower still. Which I am planning to do when the weather gets more pleasant later this season.

I watched a lot on the web about things to look out for. Like using a SWR meter. And some other technical details.

It all sounds really complicated to me. RX doesnít really have much technical details to work. But for TX I read several topics talking about risk of the radio burning from the inside when the SWR doesnít match or something.

If anyone has a easy list of tips and/or suggestions I would love to hear them. After I heard about the things that could happen when the antenna isnít attached the right way (the radio might blow up inside, etc) I just unplugged the whole rig and itís sitting in the corner collecting dust.. I really want to be able to experience the real TX without worrying about my radio losing a capacitor or smelling smoke after pushing the TX for a while.

Anything is helpful and appreciated!

Kind regards,
Telegrapher.
Title: Re: Questions CB and TX base station project
Post by: Stretchyman on March 21, 2019, 0727 UTC
You wont need a TOWER for a CB antenna, just a pole, just bolt it to side of the house.

I guess CB is more popular in the US? it's virtually non existent in the UK.

Yes you will need an SWR meter and it's not complicated to use, just checks your antenna and cable/connectors are good and the correct impedance (50R).

You wont get very far with a CB unless the sunspot cycle is peaking and it's VERY low at the moment.

I'd buy a SH Ham rig and use much lower frequencies as you will get out a lot further.

You'll need a bigger antenna tho'!

Str.
Title: Re: Questions CB and TX base station project
Post by: IZS4 on March 21, 2019, 1446 UTC
I agree. CB radio is not nearly as active as it was years ago and the sun spots are terrible right now. 'A guy I know" did work a lot of DX from 27.385-27.800 mhz back in the 90's. You should save up and buy a used HF transceiver with general coverage receive. Prices have come down quite a bit. Once you have that you will have a great receiver for the time being and be ready to transmit if you choose to become licensed later on. Building wire antennas is very simple. Especially for receive. I was able to buy an HF rig while studying for my General class. It was great motivation to study. Kind of like having a car that you can't drive!
Title: Re: Questions CB and TX base station project
Post by: IZS4 on March 21, 2019, 1454 UTC
One other thing to mention is that with any receiver or transmitter you need to have a good earth ground. As far has using a wire antenna as long as you have proper feedline with no shorts etc you can do use a simple formula for finding the wire length. FREQ divided by 468 for half wave or FREQ divided by 234 for quarter wave. Once this is done you should be within a safe SWR range and then you can fine tune the antenna. A half wave dipole for CB would be approx 17' 2'' long.
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 22, 2019, 1353 UTC
Get your CB antenna outside.  A dipole will provide you with better DX performance (generally) and a vertical (homebrew or buy one of the commonly available base station CB antennas on the market, there are lots of options) will give you better local communications capability.  If you go with the dipole, get it high up in the air.  A vertical mounted high will give you better local coverage.  27 MHz actually works quite well for local coverage with a decent antenna setup.

CB is still popular in the USA, although there is considerable variation depending on where you're located.  CB DXing (and freeband DXing) is very popular in the USA and the Americas in general.  In some areas, local AM or SSB "nets" exist.  Where I live there are several "town channels" or "city channels" in use, basically a home channel that various CBers will hang out on.  The local SSB operators hang out on an out-of-band frequency and the AM operators use channel 14, 22 or 33 depending on which group you're talking about.  Once you get out of the city the rural areas will have a "local channel" or "home channel" that is used for standby purposes.  Trucking companies, construction sites and trucking distribution hubs have their own channels.  So yes, it is extensively used in the USA. 

You'll notice a big different in TX and RX performance with the right antenna for CB.
Title: Re: Questions CB and TX base station project
Post by: Josh on March 22, 2019, 1651 UTC
Most cb users employ a vertical antenna, so if the dipole isn't vertically polarised you're hindering local comms quite a bit.

The dx will never notice what polarity the signal starts out with, as once the signal hits the idunosphere it changes polarity, so for dx, polarity is out of your control.

The great thing about 11m/10m is it's often possible to get a antenna up a wavelength, where some magic happens compared to when the same antenna sits only a 1/4 off the ground or at ground level.

Also, the vertical will almost always have a lower angle of radiation, happily this is best for local and dx comms both at this frequency range.


nerdstuff;
https://www.w8ji.com/VHF%20mobile%20vertical.htm
http://www.antentop.org/w4rnl.001/gup8.html

In the above infos we see that half wave antennas are best for getting more power out at a lower angle of radiation than 1/4 or 5/8 wl antennas.
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 22, 2019, 1759 UTC
Josh makes some good points.  I've had excellent DX results with an 11 meter dipole and various verticals - specifically a homemade 1/4 wave ground plane based off a 108 inch steel whip (102 inch whips are also commonly used) and a ground plane system.  The Antron-99 or A-99 type antennas (verticals) are also quite effective, especially when used with a ground plane kit. 

As mentioned, get the antenna up high and, if possible, use a vertical.  Ideally you would want to have both a dipole and a vertical and the capability to switch between the two but space limitations and other things can make that impractical.  Use high quality coaxial cable to connect your antenna to your radio and make sure to check your SWR with any antenna installation you do. 

What sort of CB capability are you looking to have?  Basic 40 channel AM?  40 channel AM and SSB?  Freeband AM and SSB (access to the 40 legal CB channels plus frequencies above and below the CB band?) or do you want transmit capability for all of HF?  That is, 1.6 to 30 MHz instead of 26.965-27.405 MHz (40 channel CB) or 26-28 MHz/26-30 MHz (freeband 11 meter CB). 

If you're going to go through the trouble of setting up a base station CB antenna I recommend getting a radio that can do SSB in addition to AM.  Access to the frequencies above CB channel 40 and below CB channel 1 - aka the "freeband" or 11 meters, roughly 26 to 28 MHz, with the CB band occupying 26.965 MHz to 27.405 MHz and SSB means you have DX capability when the conditions are right.  Unfortunately right now the solar cycle isn't very supportive of 11 meter DX but you do have sporadic-E propagation and of course local communications. 

CB is how many radio hobbyists first got into the magic of radio.  It's how I started, with a basic 40 channel AM RadioShack mobile CB radio and a magnetic mount antenna.  CB has a magic of its own and is a great springboard into the exciting world of radio.
Title: Re: Questions CB and TX base station project
Post by: ChrisSmolinski on March 22, 2019, 2007 UTC
I have a dipole for 11m, not sure how high it is, perhaps 40 or so feet? Seems to work pretty well for DX when the band is open (which if course is not often during this part of the solar cycle). It does pick up locals, but reception could indeed be hindered by the polarization. I'm not enough of an enthusiast (yet?) to put up a vertical.
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 23, 2019, 1146 UTC
Since most local comms are vertically polarized (as previously mentioned) your local performance will be reduced with a dipole.

I've experimented with a sloper-type wire antenna (with a tuner) on 11 meters and have had good experience with local comms - think of that as almost sort of kind of vertically polarized.  I'm sure a proper vertical up 30-40 feet would give you really good results both locally and (when it happens) with long-distance skip propagation.

Title: Re: Questions CB and TX base station project
Post by: ThaDood on March 23, 2019, 1902 UTC
Some of my 1st CB indoor set-ups were portables. 40 channel CB portables that put out a 3-4W carrier on high power, and dropped down to 2W, and some down to lower than 1W, and use the built-in telescopic whip antenna, powered by a 12VDC - 2AMP power supply. About as plug & play as you can get with CB, and some of those older Radio Shack portables from the 1970's, 80's and 90's, were great units that sounded good and were very versatile. Many had External Antenna and MIC connectors. I've surprised some ops when I've told them that I was on a Realistic TRC-221 portable and have had responses like, "That's a portable?!?! I thought that you were base, or mobile!" Just another way to start out in CB. Location is everything as well. Are you a hilltopper, where a portable can get out +20 miles, or are you down in a gully, (Like me.), were you are lucky to hear 5 miles? I've never lived anywhere totally flat, like the Texas Panhandle, but I've been told that +10 miles is nothing in a location like that. A passing thought on another option to consider, and fairly affordable. Most being sold on ebay are from hunters that used these CB portables to hunt with 30-some years ago, but now use FRS, or MURS. 
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on March 24, 2019, 1029 UTC
Hello all, thanks for the nice responses. They are very useful for my summer project I am building throughout this year. I just hooked a vertical CB antenna to the wall near a fence covering my small garden. In the middle of that garden is a antenna pole of 3 meters height with a dipole on top. Covering 24MHz in the total length from both ends of each pole to the other is 3.1 meters in diameter. The center of the dipole is at 1 and the poles are 1.5 meters long each. It worked nice for my first contact. I heard a response saying yes I can hear you but thereís a lot of noise in the background. Tested with the vertical antenna last night but I did not get a response this time. Maybe the conditions arenít that good indeed right now. I live in the Netherlands near a little town where some farmers live. I hear a few on band 7 and 10 during the evening. AM seems to get better to the other end who heard me testing than the FM mode did. I know that most AM stations are from other countries I hear on my little handheld radio. So that makes me think AM travels much larger distances than the FM signals do.

The only little thing I noticed when first operating the CB radio all inside my apartment was that when TX in AM mode, I heard some speakers turn on or make a popping sound even without being connected to any audio system. Maybe the RF is strong enough to feed the speakers lines and activate them somehow  ???

I am planning to get a HAM license later when things get more quiet in my daily routine. I am at the moment just trying and experimenting with little things to get an idea of how to take care of it. So when I have my final project build I donít face the old problems I may experience during this first experimental stage.

The only bad side here is thereís no radio shack or anything similar to go to pick up stuff I need and get information directly from the store. All has to be done mostly on the internet these days. Which gives me less space to talk about everything I do. But Iím glad I found this forum as itís dedicated to all about radio :)
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 24, 2019, 1157 UTC
RFI (Radio Frequency Interference) is quite common with home stereo systems, basically the speakers (and the wires connecting them to your stereo) are picking up your signal and thatís whatís causing the strange sounds.  AM CB radio is notorious for causing these issues. 

There are some easy solutions out there.  Get yourself some RF chokes (theyíre little things that snap onto cables and wires and filter out RFI - commonly sold as ďinline interference filterĒ or ďinline noise filterĒ). 

Noise Filter Cable Ring, VSKEY [10 pcs] Anti-Interference Noise Filters Ferrite Core Choke Clip for Telephones,Tvs,Speakers,Video,Radio,Audio Equipment & Appliances Power Audio (10pcs 3.0mm) https://www.amazon.com/dp/B078XKHLKG/ref=cm_sw_r_cp_api_i_Mc3LCbZD40YCW

^ are what you want.  Install them on your speaker cables and on the power cables for your audio equipment itself.  Iíve had success those - I had major interference with a CB installation I had causing interference to my roommateís hi-fi system - he could hear every word I was saying into the mic coming out of his speakers. 

I got a bunch of those snap-on filters and attached them to the speaker cables (three on each line, one as close to the speaker connection as possible, one in the middle of the cable run and one as close to the hi-fi amp speaker connection as possible), installed another on the line-level audio connection from the turntable to the PHONO input on the amplifier and yet another on the AC power cables for the turntable and the amplifier and it solved the interference problem. 

Also, look into getting a low-pass filter for your CB station (installed between the transmitter and antenna).  CB transmitters, like all transmitters, produce harmonics (so in addition to signal at 27 MHz, it makes a much lower power signal at 54 MHz, then an even lower power signal at 81MHz etc).  Putting a low-pass filter that stops all signals above 30 MHz will stop these harmonics from making it to your antenna and help reduce potential interference issues.  Itís also good operating practice to use a low-pass filter anyway. 

Title: Re: Questions CB and TX base station project
Post by: Stretchyman on March 25, 2019, 1320 UTC
Didn't realize you weren't in the US!

Not much on CB in the EU apart from the usual 'noise' from Italy.

With the sunspot count at an all time low I'd stick to much lower frequencies. Above 25MHz You'll here nothing from anywhere other than very local traffic and there won't be much.

However in 5/6 years time it will be rockin'!

Good Luck.

Str.
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 25, 2019, 1536 UTC
In the US (and the rest of the Americas, for that matter), CB radio is the de facto standard long-haul trucker radio.  Even with modern cellular phones and satcom systems (GPS tracking and satcom telemetry systems are very popular with trucking companies) CB radios can be found in the vast majority of 18-wheelers in the USA.  27.185 MHz AM (CB channel 19) is where most of these radios are tuned.  American truckers make extensive use of "export radios" with additional frequencies above and below the CB band, often with a designated "company channel" that is outside the legal 40 CB channels. 

In addition to those types of trucks, CB is heavily used for work site communications between trucks delivering, sand, gravel, building materials, etc.  In more rural areas it is common to see CB antennas on pickup trucks (often used by hunting clubs).  In the part of the country that I live in (roughly halfway between Miami and the Canadian border on Interstate 95) once you get into the rural areas nearly all pickup trucks have CB antennas on them, usually in addition to a VHF antenna (for either VHF business band, MURS - https://www.hfunderground.com/wiki/index.php/MURS (https://www.hfunderground.com/wiki/index.php/MURS) [VHF CB], VHF marine band, 2-meter amateur or some combination of those).  CB base station antennas are also a pretty common sight in rural areas (at least in this part of the USA).  Even in the city, there's a healthy local AM and SSB CB presence.  Most of the SSB CBers are also licensed hams who prefer the more "laid-back" atmosphere of 11 meter AM/SSB vs. 2 meter FM for local comms. 

CB antennas are also commonly found on Jeeps and other SUVs that are used off-road.  Some Jeep/4x4 off road clubs require their members to have 40 channel AM CB radios installed for vehicle-to-vehicle communications. 

So yes, CB is still very much alive and active in the USA.  Even if the OP's local CB scene isn't very busy, he will have a blast once the sunspots come back up.  :D   
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on March 25, 2019, 1730 UTC
Yeah I noticed a few truckers from like Poland that drive all the way down to deliver goods. I discovered a local community here as I hear every evening especially when sunset a lot of talk on band 7. Right now I heard a few conversations. Little noisy but some are close range and came in clearly.

I still havenít got my hands on a SWR meter so I donít TX that much at the moment. Only a few test calls a week to see if someone responds back.

Itís kinda fun to have my first TX device now and I think I can learn a lot from it and take that experience with me to the radio exam for HAM radio. Funny the people locally heard me when I was using my little dipole in the garden as TX antenna once. Operating at the standard 4Watt output. Iím also thinking about buying a amplifier to boost the power up to 250 watt later.

Nice stories tho. I appreciate all the tips and info I have already got from this forum :)
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 25, 2019, 1811 UTC
Truckers from Poland?   

So you're not in the USA?  By "Band 7" I assume you meant Channel 7 - 27.035 MHz (or 27.030 MHz on the Polish/old Russian/CIS channel plan). 
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on March 27, 2019, 0925 UTC
Yes I live in the Netherlands (Noord Brabant) Europe.

On channel 7 indeed I heard local traffic from farmers who just were talking about equipment and other things usually amateurs and hobbyists talk about. I heard stuff like TX amplifiers and boosting signal over 200 watts so I assume they are talking with each other from their base station. They are always heard on the same channel so itís a local talk group I think. On channel 10 I heard also once talk about dx CBíers and they did send results to each other about the AM and FM results. So I guess thereís a little amateur activity on CB here. Thatís why I kinda want to give it my first shot for TX experience. Planning to do dx with my base station when everything is in place. On the listening side, Iím still working on the antenna. Beside my dipole I want a full band antenna like PA0RDTís mini-whip or something better. And maybe the best SDR dongle on the market. I currently have an RTL-SDR dongle with two antenna outputs and a black cover. Itís not found on their web shop so I think itís either an old dongle or maybe from a different manufacturer. But it works fine to me. I catch a lot of amateurs already and also few number stations Iíve seen on it last year. The English one starting with ď000Ē is the most common received here with my little setup.

Besides my digital equipment I wanna do the real work on my analog radios to get the real feeling like almost every SWL has been through in the past with their nice tube radios.

My radios on the analog side are the USSR-types. (P-250M sometimes called R-250M, and the BC-224)
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 27, 2019, 1741 UTC
Those old Russian (USSR) radios are pretty cool.  They're quite rare in the United States (although surplus military gear is popular within the amateur radio community in the United States in general).

Sounds like you want a CB radio that does AM/FM and SSB or you want an all-mode HF radio to cover the entire HF spectrum instead of limiting yourself to the higher portion of the HF band (roughly 26-28 MHz or 25-30 MHz).  Both analog radios you have are receive only.

You can get a multi-norm CB radio (programmed with CB frequencies for various European countries) for relatively cheap.  The inexpensive multi-norm models will only do AM and FM modes, however.  For DX, you want SSB capability. 

Something like a Superstar 3900, Superstar 6900, Anytone 5555, Anytone 6666, CRE 8900 or similar multi-mode 10 meter/11 meter radios will give you AM/FM and SSB capability.  I know in Europe both AM and FM are used on the CB band for local communications.  RM Italy makes decent amplifiers for HF and they are commonly used on CB.  I have a RM Italy KL 203P amplifier that easily does 125-150 watts output with only a few watts input.  I actually had to lower my CB radio's output power to prevent the amplifier from being overdriven.  100 watts is really all you need. 

If you're going to spend the money on a nice AM/FM/SSB export radio or multinorm CB radio plus an amplifier, you may want to look into getting a used HF amateur transceiver instead.  Most HF radios do 100 watts out of the box, no amplifier needed...and they cover the entire HF frequency range instead of just the CB frequencies.  Some operators (myself included) like having stand-alone CB radios in addition to full-coverage HF radios even though the HF radios can transmit and receive on the CB frequencies.

If you want to do higher power make sure your antenna can handle it (and then some).  From what you've told us, it seems like a vertical CB antenna is probably your best option. 
Title: Re: Questions CB and TX base station project
Post by: Josh on March 27, 2019, 1817 UTC
The neat thing about 10/11m is a watt can work the world if the band is playing (that's true for any band however). For dx you need the band and a decent antenna. The prob is there's so many operators congregating on the few cb channels, you need power to be heard above the din. I imagine the number of cbers far outnumber the HAMs of the world.
Title: Re: Questions CB and TX base station project
Post by: R4002 on March 27, 2019, 1947 UTC
The neat thing about 10/11m is a watt can work the world if the band is playing (that's true for any band however). For dx you need the band and a decent antenna. The prob is there's so many operators congregating on the few cb channels, you need power to be heard above the din. I imagine the number of cbers far outnumber the HAMs of the world.

Oh yeah.  Although I believe in Europe CB is closer to a hobbyist thing vs. a practical/work-related thing like it is in the United States and the rest of the Americas.  Of course, there's a lot of business/trucking/taxi cab dispatcher use of CB in Europe and Russia. 

Get your feet wet with CB/11 meters.  I recommend getting a radio with SSB capability if you have the means.  I know that Poland has an active SSB CB scene in the lower to middle portion of the 26 MHz band (roughly 26.2 MHz to 26.5 MHz) in addition to AM/FM activity on the regular CB channels. 

Its always better to get a high performance antenna and an entry-level or mid-range type of CB radio instead of getting a high performance CB radio with a mediocre antenna.   
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on March 31, 2019, 1703 UTC
Yes I really want to get into TX this summer as soon as possible. I currently have a CB radio from Midland I got in a local store (it wast the last CB transceiver they had in stock so I kinda feel lucky about that) Iíll send a Imgur link with images of my stuff after this message.

Further I am also experimenting with a raspberry Pi 3 on FM TX which is also very fun to do. Here where I live I know a few other pirates that do the same thing. But they use like 25 - 30 watt transmitters in their backyard. I hope to get my hands on something like they have too. As I spoke a local pirate and asked about the troubles that might be possible to face. He told me that he is doing this hobby for over 6 years and had a few visits from the local police. But they didnít take him down as he was and still is transmitting on a empty frequency which is not causing disturbing results. So here in the Netherlands itís accepted as long as thereís no interference. I always dreamed about having my own radio station and teaming up with others. Thatís kinda the direction I want to grow to beside having a license for ham radio. I still need to get into my radio exam later. First I want to get some practical experience and a little fm transmitter with 5 watts is good for the long run. And the CB for contacting like a ham does.

My antenna is indeed a vertical (can handle more than 100 watts ) currently mounted on a metal fence. Itís not placed in a ideal location but at least itís now outdoors instead of sitting indoors on a empty computer case ;)

I canít get my hands on a SWR meter yet as I asked a few local stores if they had one. None of them had any kind of radio equipment. I wish the days were still there when stores like RadioShack and alike did exist in town. Now everything needs to be bought from the web these days which I donít really like.

Hereís a list of pictures of my most frequently used radios. Including the CB from Midland and a few USSR radios / others.

Thanks for the responses once again.

Kind regards,
Telegrapher
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on March 31, 2019, 1708 UTC
Hereís the link to my equipment:

https://imgur.com/gallery/FDG0qhU
Title: Re: Questions CB and TX base station project
Post by: R4002 on April 08, 2019, 1924 UTC
How much activity have you logged on your Midland CB radio with that antenna setup?

Title: Re: Questions CB and TX base station project
Post by: Josh on April 09, 2019, 1717 UTC
I see you're a fan of radios that can cause bodily harm too!
Title: Re: Questions CB and TX base station project
Post by: R4002 on April 10, 2019, 1236 UTC
I've done some listening on Russian and Eastern European-based SDRs and I've noticed a lot of freeband or marine/pescadore like chatter in the 2-4 MHz region, most of it in AM mode and in Russian language.  If your USSR radios can receive that frequency range...it might be interesting to set up a wire antenna and do some listening in the evening. 

Old military radios are always cool.  The fact that yours are from the Soviets is even cooler.
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on April 15, 2019, 1424 UTC
Yeah I bought those sovjet radios because they link to my first shortwave listening experience since my childhood. Right after that night I became addicted to radio hobby and alike. My interest in radio all started when I discovered a mysterious station on the shortwave band. The Buzzer (UVB-76) which I wasnít able to get out of my head after the very first day. Following it for 10 years since the first time Iíve heard it on my little handheld world radio I got as a child back in 2009 :)

On my midland Iíve discovered a lot already in 2 locations. One here at my main house and one in a big apartment with a balcony and a large roof where I mounted a long wire all the way from the window to the end of the roof (about 50 meters long) and discovered 7 CBíers in 3 hours evening time. (From 7pm to 9pm) 

Here at my shack I discovered 4 CBíers so far. With a Gipsy dipole attached to the Midland Alan gave me great success. Even on my SDR I can catch CBíers with a long wire antenna :) so I expect to see a lot more in the summer season when the band is more clear. All I need to get is an SWR meter to test the current installed setup. If it all fits within the limits I am ready to DX when the summer arrives :)

The next thing I want to do is getting a active antenna for my SDR (probably gonna be the PA0RDT miniwhip antenna) and building a stable tower to mount it on. My current tower is only 3 meters in length. My goal is to get it up a little higher to about 5 meters so it sticks above the walls around my little garden. Allowing more free space to radiate. I bought 10 meters of RG58 Coax cable to mount on the new antenna I want to buy soon.

Out of all my radios I have the best one to me seems the R-250M which has a very good noise filter to get almost any signal in clearly without disturbances. Using the TLG function with the tone adjustment wheel. The radio has only one downside which is, after listening to something for a while the tone isnít always on the position where I set it to. Maybe itís something that I need to fix inside the radio. It gets a little off frequency after an hour or so without turning the dial. I got the manual for it but due to my lack of knowledge I wonít open the radio yet. I think I easy mess things up inside the circuit so I am first going to read the manual (itís German, a language I also need to learn) and search info about every single part I canít figure out what it means. The last thing I learned about circuitry was how to read color codes on different components. That kinda describes how much knowledge I currently have. Almost nothing  :-[
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on April 15, 2019, 1657 UTC
@ Josh - Radios that cause body harm? As in high voltage risk or something else? You make me curious!
Title: Re: Questions CB and TX base station project
Post by: Josh on April 15, 2019, 1844 UTC
@ Josh - Radios that cause body harm? As in high voltage risk or something else? You make me curious!

Lol I mean radios that weigh as much as the operator almost. I have two R390As sitting on the floor because I fear my tables are not worthy of their girth. Also they have high voltage flowing around their inners so they can actually be deadly if provoked.

:D
Title: Re: Questions CB and TX base station project
Post by: R4002 on April 15, 2019, 1901 UTC
Some radio ops argue that the only real radios are the ones that can kill you (via high voltage and/or crushed under a pallet of R-390As or a BC-610 transmitter). 

When I first got into radio...my first radio was a RadioShack (Realistic) TRC-415 40 channel AM mobile CB radio and my second radio was a Hammarlund HQ-180-A general coverage receiver (shortwave or HF receiver).  The HQ-180-A was a real beast.  I connected it to a 100 foot piece of wire as an antenna and heard signals from all around the world.  I had experienced the magic of radio and I've been involved in it ever since.  I was about 8 years old at the time. 

Lots of high voltage flying around in those old rigs.  I imagine your old Soviet equipment is similar.  There is something to be said about the older tube-type gear (the American expression for those types of radios is "boatanchors").  Plus, for AM work, its hard to beat the older-generation equipment.  I bet your Russian radios sound great on AM mode. 
Title: Re: Questions CB and TX base station project
Post by: Telegrapher on April 28, 2019, 0841 UTC
Yes they surely sound better than my SDR, high end Roland music gear, and Some expensive transistor radioís i bought when I was still a kid. The R-250M is the most clear in sound even with the BFO wheel I can listen to my favorite nostalgia on 4625KHz at night without interference issues. I have only one little thing that I still need to figure out how to operate it. While listening to the 80 meter band especially. The BFO has a high pitch noise that I canít get rid of. While turning the wheel to either the left or right end, thereís a second noise always to be heard right through the amateurs speaking.. which makes it almost impossible for me to listen clearly to them. I think it links to a lot of RF-interference as I always see on my SDR radio spectrum in the 80 meter band. So maybe the focused lines on the spectrum, spreaded on the waterfall like a fence, is the cause for the second tone on the BFO mode. On 4625KHz there arenít that many of those lines to be seen so it makes sense that that might be the issue.

By the way, the next thing I would love to add to my shack is a surplus LW/AM radio only. As the R-250M doesnít cover those bands. I just bought a active mini whip yesterday and itís mounted outside in my garden to the main tower (3 meter pole) which greatly improved my reception on the R-250M. Almost no fading of signals is a nice thing I discovered right after turning it on. The height isnít that good but Iím planning to get this little thing up a few meters more. Amazing how such a little antenna can provide me excellent reception that I usually needed a 50 meter long wire for to receive similar results. :)

Yesterday I was listening to some kind of radio orchestra trough the R-250M in AM mode. (I think it came from radio Romania international) the sound was very beautiful and pleasant to listen to. No noise or interference. Just crystal clear like back in the early days :)
Title: Re: Questions CB and TX base station project
Post by: CoolAM Radio on April 29, 2019, 1530 UTC
Hi Telegrapher!

Check your private mail!

Andrť
CoolAM Radio - Shortwave
the Netherlands