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Telstar Electronics
United States
Приєднався 22 січ 2011
Telstar Electronics has been designing and manufacturing premium electronic products since 1995.
PROTO - NoiseBuster Noise-Canceling Power Microphone Array...
Superior noise cancelling using dual differential microphones.
Переглядів: 137
Відео
SkyWave DX600T Rev-B RF Linear Amlpifier
Переглядів 9803 роки тому
SkyWave DX600T Rev-B RF Linear Amlpifier
SkyWave DX300 Rev-C RF Linear Amplfiier
Переглядів 8013 роки тому
MRF300 Single-Ended Tuned RF Amplifier... 350W Output from a Single $55 Device! Very High Efficiency... Runs Cool Class-AB Temperature Tracking Bias Reverse Voltage Protection Fused High Reliability Design
CB Radio 1/4-Wave Ground Plane Antenna Project Completed...
Переглядів 3,4 тис.4 роки тому
CB Radio 1/4-Wave Ground Plane Antenna Project Completed...
Palomar ERF9530 MOSFET - Just Another CB Radio Scam...
Переглядів 2,4 тис.4 роки тому
This is NOT a high frequency transistor. The datasheet is a kluge of incorrect information, and the device performance at 27MHz is horrible. This is just another scam targeted at the CB radio operator...
DEVELOPMENT - Class-AB Amplifier Temperature Tracking Bias Circuit Demonstration
Переглядів 3,7 тис.9 років тому
A quick demonstration of a new prototype temperature compensating class AB biasing circuit for RF linear amplifiers.
It is amazing to hear someone putting low pass filtering on amplifiers. Is the filtering on both input and output? Thank you
Harmonic filtering on the input? Completely unnecessary since the radio driving has virtually no harmonic content.
Pi filter on output...
Hello, What type of material was used for the L-Matching Network? That is an amazing setup, it would be great for my HOA. Thank you
It's just an L-match... using #12 solid copper wire and a mica capacitor.
Magnet wire air coil & ceramic capacitor used for L-match...
Nice Video Brian. Looks Great and sounds great!!
I'm shipping the first proto unit today to a guy in PA... about 100 miles south of you. We'll see how he likes it.
Very nice worth trying ,all that wind in the truck yep.thanks
Yes, this mic was designed primarily for the mobile environment... but certainly can be useful anywhere.
Looks good
This works very good... one of my better ideas lately... LOL
Cool! Glad to see it’s a success! Neil H.
It's a very unique experience. Power mic audio gain up close, with virtually no background noise coming through.
Hey it's your favorite customer! Is this up on your site for sale yet? I did not see it on site? Yes it is "Two way radio and that is what it is all about"!! I have asked about electronic switching in the past and people always poo-poo'ed it! I looked on ebay as well! Can't wait to try one!
This is still a prototype... but the interest in this seems pretty high. Not sure how it will be offered yet.
Sir where did you get that slab of heat sink? I like it.
heatsinkusa.com/
Ive heard these are not true RF devices but more suited for power supplies and are being used for RF applications anyway.
Absolutely correct... these are FETs characterized at 1MHz. They have virtually no gain at 27MHz.
@@TelstarElectronics Are these the same mosfets used in Rocket amps?
Yes...
@@TelstarElectronics Yes are they any good? for the device only costing 5$ they sure are expensive amps.
You get what you pay for. Good RF devices that work at 27MHz and run on 12V cost about $50 each... so you can figure how those 1MHz $5 devices work.
1:1 ratio is NO gain has to be over driven just to work.
LOL... it's not quite that bad... but the gain at 27MHz is very low alright.
Could you put a kit together for me?
I don't sell much of anything anymore. People are not willing to pay for quality equipment. So, I only make good stuff for my own use.
@@TelstarElectronics I hear that.Thanks anyway professor.
Looks good. whats the input power require for 650 watt and secondly the tuned ckt. module - is it broadband or meant for any particular band
www.telstar-electronics.com/SkyWave%20DX600T.htm
The 4 watt 29 was driving it good.Pegging that 500 in the corner.Pretty badass little amp!!The 29 might be doing 5 rms.
This is the best amp I've ever designed. I use one every day talking skip on channel-28. Everybody knows the ol' professor...
@@TelstarElectronics Good job!!!
What's the Voltage requirement
48V
Now you need to make a 4 transistor version to about 1200w to compete with the bigger ones with the single 400 dollar chips in them.
Compete? With those meatball designs out there made in a garage? Those are nothing but poorly built prototypes...
Saying a long loud "AUDIO" is a much better indication of real world talking power. Some of my elmers would really give me a lecture about whistling to check audio and power. Beautyful build BTW.!
Since you're looking for a peak... actually, the whistle is likely better. It's a much purer frequency that doesn't vary in amplitude much.
Dude we need to ask you this man but our group is walking a fine line. TAFT doesn't bash shops or builders because we are shops and we have to deal with the builders. It's business. These Palomar transistors seem like crap to some of us and a godsend to others. Shops make a nice profit from maxmods and ERF2030+ Mark Sherman of Fine Scam CB swears that these transistors are the best ever including the max mod. Because they supposedly "fix" the radios flaws. Two other guys did videos going back 2-3 years that said these transistors and the max mod were a scam. They got attacked by Mark Sherman and other shops relentlessly. Both of those guys took their videos down (and we have copies still) and the rumor is that Palomar threatened to sue both of them because they did tests like you did and the transistors didn't exactly live up to the claims. Palomar ever try to sue you? Looks like you independently verified what they said several years ago so now I really do believe these other guys that said these transistors were just relabeled junk.
Well, I don't have to deal with "shops" or "builders"... so I just tell the truth. Palomar sue me... LOL! For what?...telling the truth? Oh, and you're right... the MaxMod is also a scam.
@@TelstarElectronics I thought maxmod was the real thing until I saw a gentleman present and go over the math equations that disprove the maxmod. Then he tested it and the results matched the equations. I thought those videos got Palomar upset because he took down most of the videos without explanation. That's why there were rumors that this guy got threatened. If not by Palomar then it was trolls for CB shops like Mark Sherman. In fact, Mark Sherman still attacks these people relentlessly because they proved his beloved maxmod and ERF2030+ were BS and I am sure it threatened his scam CB shop business in the Winnebago. After all he gets around $400 to install the maxmod and the ERF2030+ into a stryker 955 because otherwise, according to Mark Sherman, the radios will "explode" or "catch fire" If you didn't get threats like they did then I bet Mark Sherman's losers and trolls are the reason.
Yes, radio related scams make the scammers a lot of money. They get very upset when you expose them. I don't have a thing to do with them, so I don't care if they like what I say or not...
Do these amplifiers work on other bands like 20, 40, and 80 meter bands?
The DX250 and DX300 will not work on those those bands because they have a tuned output.
I still have your DX150 KIT...
Your amplifiers have clean output - practically free of harmonics... I wish I knew where to buy the metal chassis.
Metal and plastic chassis are available from numerous places. I prefer the plastic... much easier to machine.
nice antenna. cb skip = fun
Yes, this home-made unit works great... makes no modifications to my house, and is very portable. The resonant match realized with the matching network inside the box gets this aerial to 1.1:1. It may not look like much, but the skip performance is awesome.
what is the best fet to use in a 10 meters amplifier?
I sure like the MRF300... a great bang for the buck!
New to the base station stuff only used plug and play mobile equipment. Love your video and your build is absolutely beautiful!!! Can you explain the matching network part and maybe a build spec? I'd love to try and build something similar. Last question - if the antenna were mounted up higher wouldn't you be better off? Thanks; Shawn Seattle WA
I use the antenna mostly for skip... so antenna height is not important. As for the matching network... a simple L-match.
@@TelstarElectronics what kind of impedance were you getting before the match, with the radials laid out flat like that? the 3'x3' aluminum bit- was that based on a calculation/some part of a wavelength? thanks- very interesting build
The impedance without the matching network was about 1.6:1. The 3'x3' aluminum plate was not based on any calculation... but more on mechanical and wind stability. I can tell you that it has survived a storm with 100mph gusts! Since it's only about 1/4" off the ground, the wind is not able to get under the aluminum plate enough to be an issue. I've been using this antenna for many months now... and it's surpassed my expectations for performance.
how is swr?
There's a matching network inside the box. The match is 1.1:1
Any one know if this lil ' issue still exists on this transistor I'm gone upgrade my Radio with 5 of this ( probably they update them) Question to a professional person... Thanks and advance... 73s
Of course it still exists... this is a 1MHz transistor. Anyone who thinks it will work well above 5MHz, doesn't have a clue.
@@TelstarElectronics thx for Reply thx for the info 👍🏼
"The CB crowd" Hey....I represent that remark 😂
I can tell from your response that you're not part of "the CB crowd" I was referring to... :)
More snake oil, isn’t this just another rebranded device? But what about the shop that puts them in every radio and claims he’s the only one in the world that knows how to tune a radio. I saw it on the internet so it must be true....
Yes, these are nothing more than general purpose 1MHz MOSFETs... that have like 3dB gain at 27MHZ. Rocket Box and Palomar amps use them. They work like crap.
Nice. I need something like that so I don't have a big intrusive tower in my neighborhood. Someday I'd like to set up a base at my house
Exactly right... I wanted a semi-portable antenna with some good gain... that I didn't have to mount on the house.
Nah... the Zepp is too big! I don't have anything to string up a 1/2 wavelength vertical. My 1/4 wave ground plane is all self-contained and needs only a surface to set it on.
Thanks for an Engineer's perspective. Was looking for a 7530 replacement. Apparently Palomar and their 9530s are consistent with today's business model: lie, cheat and steal until caught bare butt naked; then sic your army of thieving lawyers onto the opposition and wear 'em down in court. Cant even get a King/McD burger with real beef anymore. Its either meme or pink slime filled.
There are some very clever "scammers" out there in the world...
Would like to see you work with the newer Sic Fets and GaN Fets. 👍 I heard they love volts as well.
My major focus is the low-voltage mobile environment... so I'm really not into FETs as a rule.
@@TelstarElectronics what would be a good drop in replacement for these? since they are probably a Chinese communist brand that costs maybe 20 cents each before rebranding. since you are an engineer and you have one in hand or you did a year ago. no doubt you could match it up on mouser.com prety easy. they are restricting the supply to drive the price even higher now. lits like 13 dollars a fet now. be nice if someone could bust that up a little.
There shouldn't be a drop-in replacement even considered... since these transistors are not meant to be used for 27MHz operation!
Nice to see you back on youtube uploading. I hope your move went well and you are getting settled in!
It's all good...