early Maverick 250 monobanded for 10 meters only
Вставка
- Опубліковано 29 січ 2022
- Already did a vid on this Maverick 250 when it had all the Ham bands in it. Now showing it after monobanding it and working on 10 meters. For 10 meters, pretty much any tube amplifier only needs around 4 turns of coil in the tank output circuit. Those extra turns are for the Ham bands. As you go down in frequency (up in bands) you need more and more coil and capacitance too. Its almost a 1 to 1 ratio (almost) to frequency in meters to radio of coil turns needed. 4 turns for 10 meters, so 8 turns for 20 meters, 16 turns for 40 meters and 6 turns for 15 meters. All that extra coil is useless if you are only using 10 meters though and also it has been said that most designed for CB amps won't even load on those bands anyway. All that stuff was added to get pass the FCC to legally sell these type of amps. The FCC still put a stop to that though. They required amps to be driven by 100 watts and to not work on 10 meters. Most new amps sold to this day follow that and need 100 watts drive and need to be modded to work on 10 meters.
- Наука та технологія
The knowledge you have shows in you videos. Keep up the great content. I can neve learn enough from you.
Thanks, will do!
I love watching Mr BBI. YOU However are the sweep to master. Thank you for all you do.👍
You are very welcome
Excellent! Thank you,Dan...
Thanks for listening
50 years ago...
It was a tossup as to who sold more amps, Kris or D&A. Hawks were popular with owners of rigs like the Regency Imperial and Range Gain, and the Olson Sidebander. These rigs had a reduced carrier scheme and typically put out 1.5 watts. A Hawk gave it a little more schmaltz to compete with the crowded band conditions of the early 1970s.
4 watts into a 50 ohm load is a little over 14 volts.
Tube finals can withstand a mismatch far better than transistors. Many amps of this era didn't have any input matching circuits because they weren't needed. Also, before the FCC standardized the output power at 4 watts the input power of 5 watts typically gave a 3 watt output.
When transistor sets displaced tubes amp makers were forced to add a tuned input to give the transistors a correct resistance load to prevent the voltage from getting too high and destroying them.
Before rigs like the HR2510 and the Ranger the concept of "high drive" wasn't a problem. Most CB radios weren't capable of doing more than maybe 10 watts output on AM.
Keying circuits. Ever hear of an amp made by Polycomm called a Poly-Booster? It is a 2x6883A amp made for use with the Model B low band FM radio. I have both radios. When I got the amp it wouldn't power up. Without a schematic I had to trace it out. I discovered that a relay controlled the primary power. That relay needed 12 volts DC from the Model B through the antenna connector to pull in. A fiendishly clever way to prevent CBers from using it illegally. The problem was that the 12 volts appeared on the amp's output connector. No problem, unless you're using an antenna with a DC ground. Its keying circuit is a special relay that needs the 10 watt input from the Model B to activate it. The 3 or 4 watts from a standard CB radio isn't enough. The Model B is rare enough, but the amp is extremely rare, and I got lucky when I got the amp over 10 years ago because I haven't seen one before or since.
Up here in the Mich, Oh area, it was D+A, and Palomar who sold the most. Kris, not so much.
@@tramdr Wagonmaster 390 asked me to ask you if you know a 669 from your area.
@@spaceflight1019 nope
@@tramdr okay, thanks. 390 was doing a livestream last evening and talked to 669 on 40 lower and just fell in love with his audio.
Doc, I think that this was one of my favorite videos. Probably because I have a Hawk, a Raider and a Phantom. I have the Phantom that’s on the back page of that flyer. Triple stage 12 tube no bandswitch. Please do a video pointing out what capacitors I should replace and their values. I’d like to put this thing back on the air. Not too much to ask is it? Lol
Hmmmm.
I'm picking up a 12 tuber soon . Second
First guy I ever saw use radial caps in the filter section 👌🏻
radials are usually easier to find and cheaper then axials. I use them all the time.
Really appreciate this. I've never seen the sales brochure.
Would love to see more D&A videos!
I have a few 12 tube phantoms. One of them has 6km6 tubes in it. Is there any advantage or disadvantage to running these tubes? Other than they are considerably more affordable?
Thank you for the great videos.
6km6 tubes are less costly but they have about 1/3 less power than the 6lq6 tubes. I may do a couple more D+A's. They are good amps, workhorses, but I like amps that give you more swing, like Maco or the Hygain Footwarmer.
How do you make sure its grounded out to replace tubes ? Keep from getting shocked
D+A's have bleeders, turn it off, unplug, wait 5 minutes, then get a long screwdriver and run the screwdriver across the tube plate caps, the top silver connections and a bare metal spot on the case, which would be ground.
What about a Forced Air Cooling 4CX5000A Linear.
ok, what about a 4CX10,000 or a 4CX25,000 or a 4CX50,000 forced air linear?
Can I use 100 UF 350 VDC 80c in my Maverick
Yes, but more uf's would be better and also adding some bleeders would be better too. Careful that amp doesn't have bleeders so it can bite.
@@tramdr thank you my 16 year old grandson trying to learn
I picked one up that is a single stage
Yeah the early ones were single stage and monoband
@tramdr Works good though.
IMHO, the single stage monoband ones work the best. More direct path and less to go wrong.
Do you have a way to contact on Facebook I have a older gray maverick I'm putting caps in need a little info. Thanks 73s
Best to contact me here or email me at Tramdr at Yahoo.com