I looked at the LPDA and wasn't impressed by the front to back ratio, so I installed an Optibeam OB11-5. I have been very happy with it. Mark N1UK My Yaesu Mark 5 would begin to roll back its power o
That just shows the failings of SS Amps. A 1.3:1 SWR equates to 1.7% reflected power. Any Amp that can't handle that has no place in my shack. As for tube amps, just shows the benefits of a tuneable
As for tube amps, just shows the benefits of a tuneable Pi-Network. My neighbor K6XX, the engineer at Elecraft who put the KPA500 into production and has done extensive testing of many competing ampl
I would be curious to see how these LDMOS devices perform. Has anyone any data on the M2 boxes they sell for 6 and 2 ? An HF Amp, using one or two of these devices would be very interesting. 73, Dick
Same here Rick...just went over my SWR graphs on the old T6 I just took down. 20m is the worst case scenario with almost 2:1 SWR at the bottom of the band, and decreasing as you tune up. Every other
If I can rephrase Richard's remark that says "Amp that can't handle that has no place in my shack." or Amp that has tubes without handles has no place in my shack. Herb, KV4FZ On 10/26/2013 4:05 PM,
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sat, 26 Oct 2013 21:23:01 -0400
I disagree. It's not a fault in the amp. Your and my tube amp "have tuners built in" called a PI or PI/L network that matches the high plate impedance to the low impedance of the antenna system. If y
The point I responded to was the statement that some amps fold-back with very low SWR's. Clearly the use of an antenna tuner was not included. The fact that most (not all) SS Amps have Automatic Ante
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sat, 26 Oct 2013 21:53:48 -0400
The fact that most (not all) SS Amps have Automatic Antenna Tuners just reinforces my statement. What QRO SS amps (1KW and above) have built in tuners? I've not found one yet. 73, Roger (K8RI) <snip>
see QST November 2013 page 54 review of SPE Expert 2K-FA 2KW PEP. autotuner, 6 antenna connections/memories Grant KZ1W The fact that most (not all) SS Amps have Automatic Antenna Tuners just reinforc
Donšt forget the Quadra. 73, Jim N9WW James Chaggaris President PowerOne Corp./PowerOne Environmental 2325 Dean St. Suite 200 St. Charles, IL 60175 Phn: 630-443-6500 Cell: 630-669-2241 Fax: 630-443-6
It may take some innovative fellow to come up with a SS Amp that behaves better and my mention of LDMOS devices may be the way to go. Some of the newer LDMOS devices are quite robust, and seem to be
The fact that most (not all) SS Amps have Automatic Antenna Tuners just reinforces my statement. It may take some innovative fellow to come up with a SS Amp that behaves better and my mention of LDMO
It may take some innovative fellow to come up with a SS Amp that behaves better and my mention of LDMOS devices may be the way to go. Some of the newer LDMOS devices are quite robust, and seem to be
Exactly right. Two VERY important fundamental facts are that both 1) the behavior of a power stage (linearity, efficiency, gain) and 2) the response of filter networks, are exquisitely dependent upon
beats out 48 feet every time too. Be careful about the TA program. It assumes you are in the middle of a wheat field in Kansas. In urban locations, height is everything. New homes on my street are ve
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sun, 27 Oct 2013 01:17:31 -0400
You're right, but it's over a very limited range of impedances. I have one and completely forgot it has one. Unfortunately mine has a few blown transistors...if I'm lucky 73 Roger (K8RI) 73, Jim N9WW
BULLSHIT! N6BV;s HFTA terrain analysis software uses USGS terrain data to model the behavior of horizontally polarized antennas. It is DAMN GOOD! If you live in flatland, NEC is sufficient. If you ha
Jim, You're the audio expert, but didn't Bob Carver figure out some clever variable supply voltage tricks with his big Sunfire amps? I have two and my "Signature" stereo is rated 2 to 16 ohms (1250w/
On 10/26/2013 10:57 PM, Grant Saviers wrote: You're the audio expert, but didn't Bob Carver figure out some clever variable supply voltage tricks with his big Sunfire amps? I have two and my "Signatu