The best deal a casual Google search turned up was RG393 at $13.20/foot from Tessco: http://www.tessco.com/products/displayProductInfo.do?sku=57757&eventPage=1 I saw 139 feet on eBay, but it was outr
Sorry, I finally noticed that your box wants to be on the 100-watt end of things. Make that RG303 instead. There are scrap lengths on eBay here and there, do a search for RG303 . Also - there may be
Simply amazing. You can buy new Chinese or Russian clones for $125 to $450 each, matched pairs for twice that. Not that I would... I like vintage triodes as well most reasoning mammals, but MOSFETS a
Which brings to mind a related question: What's the latest thinking about using silver-bearing solder in amp tank circuits? In the US, Radio Shack sells 62/36/2% tin/lead/silver solder for $7 USD for
[...] = "Soldering is Rocket Science". Funny, but true. :-) 73, Jim N7CXI _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/lis
On 9/10/2012 12:26 PM, donroden@hiwaay.net wrote: Quoting "Bill, W6WRT" <dezrat1242@yahoo.com>: REPLY: One thing to be wary of with any pulse type tuning device is they do not load down the power sup
On 9/18/2012 6:39 PM, Larry P. Greenberg wrote: For a good number of years, I had a Henry 3K Classic export with a single 8877. Peak power (fully tuned) occurred when the grid current was low, around
Aubrey, This applies to the AL-80/SB1000, but may apply to the 80B as well. If you pull the cover off, check to see if there's a power relay mounted on a piece of metal that's screwed onto the rear c
I'm working on a PA-76A, doing the obvious stuff - replacing the filter caps, the tantulum timing cap, the low-voltage filter etc. All well and good. What raised my question is the bleeder/equalizer
Thanks, Carl. I might as well replace all the carbon-comp resistors on the control board while I'm at it. The tubes don't show any element shorts with an ohmmeter and hi-pot fine, so I'm going to go
Those look good, but are no longer a stock item @ Mouser. Looks like 90 minimum, with a 10-week lead time. Thanks es 73, Jim N7XCI I'm working on a PA-76A, doing the obvious stuff - replacing the fil
After replacing the filter caps and equalizing resistors, I fired up the 76A today on 40m and had a couple of nice contacts. The 120hz hum problem *appeared* to be gone. The spectrum analyzer showed
Thanks, Colin. Since it's the only one standing, I'm going with your theory. This isn't a known (or heard of) issue with the design, so I'm going to choose to assume that there's a component failure
Hi Bill, I know what you mean about hum modulation on the power line and local receivers, but this is strong enough that it almost wipes a transmitted SSB signal out mixing with it, and CW signal is
Hi Jim, Yep, we tried AM and SSB both. The filter caps are brand new, and I also changed the bleeder/equalizer resistors, as well as the other carbon comps on the control board, since they were drift
I agree, Carl, but I doubt it's the case here. The hum peak at 120Hz from center is only 6dB down from the carrier when driven at 1805 kHz, and 14dB down at 1995 kHz. It's not a "little bit" of hum.
The Alpha 76A "hums on 160m" problem has been resolved. Thanks to all that responded, on an off the list. The actual problem turned out to be a plate bypass cap that measured good out of circuit with
Thanks, Jim. Allied has Vishay .01uF 6KV units in stock for $3.44 . I'll get a batch next time I order; seems they're getting hard to find. 73, Jim N7CXI Mouser has .0047 (4700pf) 6KV Vishay/Sprague
Assuming adequate core/wire sizing and airflow, can anyone think of a solid reason *not* to design a legal-limit HF amp output tank for 200 ohms, then use a 4:1 "un-un" transformer to step it down to
1500 watts 4kV, 625mA Single 8877 at around 4000 ohms plate impedance in AB2. Tnx, Jim N7CXI Sent from mobile wireless -- Original message -- From: Jim W7RY <w7ry@centurytel.net> Date: 10/20/2013 6:3