I remember those Pyramid series , they made everything from car radios , boom box speakers ETC ETC , When I had my 2 way radio shop in the 80's and 90's I was buying wholesale from Moore Sales Co. In Texas..... You just did a very great upgrade on that unit....
Always preferred 3773s over 3055s. They were supposed to be lower gain, but I've always found them to have higher averages than the 3055. Finding matched pairs in the 3773s was (for me) easier as well. It didn't surprise me to see the 3055 under 30 gain with the 3773 over 30. But a different story when you chop the top off the metal TO3 case. The 3055 is better in circuits detecting luminance levels for some reason.
I purchased a 20 amp version of the same power supply in the early 90's at R&L Electronics. I used it intermittently with a packet base station. The whole setup drew 2-3 amps maximum. A short period after the warranty was up the power supply was dead. Really dead. The primary of the transformer opened up. I gently cut open the paper over the windings hoping that the fault was near where the windings attached to the wires. No such luck. Kept the heatsink and output transistors and the trashman got the rest. I have been buying Astron power supplies ever since.
Excellent video. Is it possible that you could make a short video on how you constructed your dummy load? I would like to build one as well. Thank you for your time.
Years ago I did al lot of CB work here in northern California I still have a few of my own cobra 2000s, a couple of Galaxy 99's,Mirage 99's, and a few Texas Star amps (they were my favorites, I ran a DX1600 in my truck) and a brand new moonraker 4 new in the box as well a couple of hy-gain super penetrator 5/8 wave ground planes new in the box. Yes I am a hoarder. email me Norcal715videos@gmail.com
Very fine video, troubleshoot and repair! Brand new Astron PS konked out. Opened case to repair and was stunned...solder splatter all over, some wires pulled so tight you could pluck them like guitar strings. Same issue, very little thermal heat compound. One 0.05 wire wound balancing resistor was open, one 2N3771 cooked. Question: On the schematic in your video, why is there a small "X" marked in red ink. Thank You!
I see they spared no expense on the thermal paste.🙄☹️🤮. Well at least the transistors opened and did not short. No over voltage protection! It could have fried an expensive device connected to that cheap power supply!
Yeah, back in the day Pyramid was always considered junk up my way. At least you are able to fix yours with better quality components and love then they did in China.
Used my MK -168 on my 2N3055 and diode between pin one and two transistor bad ! I was trying to bias a new IFR520 I put in my Galaxy DX 2547! After lightening in my area,I soldered a dip socked on the final pc board position so I can change final’s quick . No matter how well antenna is grounded lightening will get you. Pyramid ps8kx took a hit through the power line! Thanks for your help JohnBoyUtah KJ7TBR 🇺🇸🎙
I need the get back into the CB/HAM radio. I still have a couple of Mirage DX-99's, I have 4 Cobra 2000's, a couple of Cobra 148s (one that I modded with the import PLL IC to get +80 and -80 channels with the +10kc switch, roger beep, echo, etc. Plus several amps ranging from an honest 250W to 2500W.
I got of my 71 yr old COVID ass took tech & general 2019 ! I got an old Ken wood 520s I restored got a Texas star 250 that I use now with DX2547. I have a 1993 148gtl , recurve no transmit 1969 final checks out. I am afraid to sent it to a shop they would take it and say it was stolen the 1993 is the last year of good quality befor China’s
Two amps for sale Palomar 300A and Maco 300 both with good tubes,there is a guy in AZ. That makes a VFO for the 148 cobra it’s sick great idea! When I sell amps will buy from a friend a Aramatron 811 , for ham can’t wait. Get back into radio. JohnBoyUtah
C2 is drawn backwards in the schematic. I didn't notice that in the original video. C3 has a higher voltage on the positive lead than the negative lead. The negative lead is referenced the the lower voltage collector supply (about 25 volts) The positive lead of C3 is about 35 volts (or about a 10 volt difference)
@@norcal715 Thank You, I see it now, C3 is on a higher potential from the other winding of the transfo. And C2 is just drawn wrong. Phieuw, I can go to sleep now. Haha Thanks!
