I'm a bit confused about something after overhauling one of these. It seems that if you leave the amplifier in the low power position that both the transmitted and received signals are required to pass via the 3x 15Ohm resistors. This is attenuating the received signals. I need to double check the value of the resistors as I believe someone has changed them. After checking the circuit diagram it does seem the power attenuation resistors are located before R1 thus forcing any signals to flow via them. This makes little sense to me. If the resistors fitted are too high a value then perhaps this is why I'm noticing this but if the resistors were of a lower value the power attenuation would do very little.
I like the dim lights. They spread the light evenly. I put an LED in my BV2001 the version with the power selector rather than 3 switches. But I put the led on a large resistor so that it is very dim more like the original. They don't hit 800W they have 4x el509 rated at between 60 and 70W each, do the math. Put it on a 1kw dummy load and you will see. If your correct them make a video of you pushing power into a large dummy load as it will be very interesting if you can get more than 300W AM FM
Interested in your comment diode protection between collector & emitter. I am rebuilding a power amplifier on a TS-120S and the 2SC2290 and 2SC2509 all test diode on BE BC and EC as you mentioned. I also tested some 30 year old 2166 and 1969 and they test diode on Collector - Emitter. My transistors are OK. Regards VK4HDA
Hi, You say the voltage it to be 3.2vdc and I have one that I think to driver is blown and I have ordered a replacement. When i check the gate voltage it has none. I checked the other 2 I have and ir is the same thing. Can you explain if this while you TX or what? I only have voltage on the drain and its 13.8?
Hello Mate. I'm the guy who bought this ol' girl off you a couple weeks ago. I have her set up in a tower block (at the top) in East London currently running into a siggie 4. I was up on 10m with her yesterday, the skip was rolling in...I have a G7 ticket and with around 350w USB she was amazing with a wicked RX (like you mentioned at the time). I have also had great reports at Dunstable Downs - barefoot with a silver rod / GPA on the back of an old transit. Wicked rig I won't be passing on! Thanks for everything mate. Mickey :)
the best i ve ever seen with the mrf477 it can burst up to 40 w on ssb with low heat .with a baby ant it is really performant .thousands of km round the world .believe me . amasing radio.
when clear channel was in business I bought one of this radio in the late 80's for ultimate performance for today you have to do total re cap and change the RF board resisters to the new heat resistance resistors
not meaning to be negative,,already given you the thumbs up ,,but thought when you were transmitting you should use the carrier control to adjust the ALC,,appears you running well out the ALC will this not damage the finals ,,? thanks shane
shaneweightman It's typical to get excessive ALC readings from a TS-450S, usually erroneously elevated. I set mine to 'taste' as I have several friends whom are critical listeners and let me know when it sounds like it's being driven just right.
Hello Weazle66. I have just found your site on RU-vid and wondered if there is any chance of you repairing my Superstar 2000. I have had it from new (early 80s) and over the years it has never let me down until it developed a fault with the PTT. It will not switch back to receive mode after using the mike. When I switch the input power supply off and back on again it starts up in receive mode and works perfectly until I key the mike again. I hope that you can help and look forward to hearing from you. Regards, Dave.
Just picked up a 200gtl from a friend all seems to work well except side band is inaudible in hi power mode...I think the power is set too high because the radio is swinging to about 150 watts pep on am in the hi power mode and 100 on the low setting...a friend was telling me he thinks it's the driver fet, but wanted to get your opinion...any help is greatly appreciated... Cheers
Hi friends, I must warn you not buy in Little Diode UK They sold me fake transistor 2SK2220 !! I'm still with claims, and I seriously doubt if I'll be able to get my money.
The Cobra 200 GTL DX is one of the best CBs I've owned. It will talk skip any day of the week. I've had it installed in my pickup for over six years. 73's
For some reason, the real LARGE screen Mitsubishi TV CRT output modules can go up to 32 MHz, and the 46" sets can do well over 2000 watts RF! There is just something about Mitsubishi. The 36"/38" sets will do well over 600 watts RF, and the Mitsubishi FLAT BACK sets have an independent power supply for the HV and and an independent PS for the audio, they have FLAT external heat sinks on the back.
I just bought one on ebay - it arrived about 1 hour ago. Very wearworn, but everything appears to function as it should - absolutely no traffic on any channel any bands though. With sun spot minimum, I'm guessing now is not the time to DX around the world !
TIP3055 TO-247 NPN Power Transistor Vcbo 100V, Vceo 60V, Vebo 7V, Ic 15Amp, Ptot 90Watt, TO-247 Package this is the one I have found same as the one in your video just couple of the smaller digits different
I have a few of these kicking around, will probably improve the bias circuit, the temptation to use my FT817 in the car with a tray of amplifiers is getting too much.
