I just acquired a Henry 2K-4 console linear amplifier. I like to run AM as well as the other modes. The Henry is rated for continous duty and as AM is closer to continous than SSB, I figured it was a
Do you still get the same hum if you transmit a CW carrier and not AM? (Mode switch in CW...)? If it's the amplifier, you should. If the mike is picking up an induced field that may be generated by t
What is your carrier power output from the amp on AM ? Mike --Original Message-- I just acquired a Henry 2K-4 console linear amplifier. I like to run AM as well as the other modes. The Henry is rated
After eliminating the driver hookup Id start by measuring the ripple on the HV. Find someone with a HV scope probe. Carl KM1H _______________________________________________ Amps mailing list Amps@co
Steve, yes in CW mode too. It's not coming from audio. Do you still get the same hum if you transmit a CW carrier and not AM? (Mode switch in CW...)? If it's the amplifier, you should. If the mike is
The 8 Henry filter choke with an oil filled .1mFd in parallel then an oil filled 20mFd cap to ground is a tuned filter, tuned to 120 Hz. If you truly have 60 Hz hum, you have a diode open in one of
Or you have a ground loop or audio issue with this setup. I see that you have no hum with the SB200. 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com
Be careful if you fix this. It's not tuned to *exactly* 120 Hz because that would cause a very high voltage to appear across the choke. Use the specified values if you replace anything. Also -- if it
John, every dc power supply has some ripple. If the power supply has a nominal output of 2500vdc and the ripple voltage is 125 vpp then that would be 5% peak modulation or 3.5% rms. I think this is 2
If supply voltage is higher than normal you may have some shorted turns on the filter choke. If supply voltage is lower than normal you may have reduced value of filter capacitor. If ripple frequency
The Henry amps I've had (several over the years) when operating properly produce negligible hum modulation at full rated power. But I asked earlier if he found the same evidence of ripple when he use
Steve, It's also present in CW mode. It's on the scope and it's heard in my receiver and others. It's present whether I use the DX-60 or the TS-570 in any mode that produces a carrier, with or withou
There is a good discussion of the power supply in the 2K4 here about half way down. http://www.qsl.net/i0jx/supply.html 73, Dan, N5AR _______________________________________________ Amps mailing list
Perfect! Then, it must be the amplifier. Have you confirmed it's really 120 Hz and not 60 Hz? If so, sounds like the choke tuning is incorrect and the tuning cap across the choke may have drifted in
Maybe not the amplifier. Hums can be really tricky. When I did that check last night, I hadn't had the ground lug on the back of the Henry tied to my station ground. I grounded it very well with 10 g
The 8' ground rod did absolutely nothing. But the bonding of the equipment together did. 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com http://lists
Still they can go bad, it has happened to me. In any case I would check it to make sure itīs OK. / Jim -- _______________________________________________ Amps mailing list Amps@contesting.com http://
I just looked at the 2k4 manual. I never had one so I thought I'd look at the schematic. I noticed something interesting. L10 ,a 50 uH choke, is connected between the centertap of the filament transf
Forums are full of reports of defective oil caps from Henry's and early Alphas. Carl KM1H Still they can go bad, it has happened to me. In any case I would check it to make sure itīs OK. / Jim -- ___
idle curiosity what does a 120cps hum sound like? is that G sharp over middle C ??? <G> chas k5dam -- chasm@texas.net k5dam Houston, TX <a href='http://militarysignatures.com'> <img src='http://milit