Hello all, Want to re-do the input matching of an old HB 8877 amp. What should I use for the cathode impedance when calculating my pi network? I recall it was something like 50-60 ohms. Also, thinkin
Carl, and company, Can you bypass the cold end of a RF choke too much? Say, I put 6 or 8 - .0047 pf caps in parallel to carry the RF current. And, the plate coke is 180 mh and it's on 160. What would
Hello all, My wife has a woman working for her at her art gallery that is also an experienced 'glass artisan', or whatever the name is, and I asked her about working with the glass vac variables. She
Along a similar line... I fought poor performing Beverage antennas for abt 2 years, before I found the problem. The black plastic boxes I used to house the transformers at the antenna feed were condu
I agree with Mark 100% Don't know the background, so I'm not taking sides. I just don't want to hear this petty bickering from anyone. Have an issue with someone? Take it OFF the reflector. 73 de Ste
Hello all, Looking for analog meters f/u/w the current amp I am building, and for any in the future. I have done quite a bit of searching on the Internet and really haven't found quite what I think I
Hello all, Thanks for all the excellent input on where to find meters. I have about 4 good choices, including a couple of offers from people on the list. I appreciate the input. -- 73 de Steve, NR4M
Another thing. Several of you mentioned the 'Meters' program used to create your own custom meter faces. I have been using this for quite a while and find it super useful and I highly recommend it. -
I think most people would use something called a high potential tester AKA 'HI-POT' tester. It allows you to put a variable high voltage across your tube from various pin combinations. There is a hig
Hello all, A friend had the filament transformer in his TL-922 fail. He asked me if I knew of anyone rewinding them. I told him I'd ask here. If he can't find anyone, I suppose he can either look for
Hello all, Figured it was time to re-cap the PS for my Ten-Tec since they are about 25 years old. The amp hasn't been used in a while so you just know what will happen if I DON'T re-cap it before I u
Thanks for the input, Dave. Been looking around and, they're a non-stocked item, like you said, or they're big $$. I have a bunch of much shorter, snap-in caps, which I've used in the past with good
Hello all, Recently picked up an older Alpha and was thinking of making the conversion to a pair of 3cx800's from the 3 x 8874's which are in the amp. Any suggestions on a source for good 3cx800 pull
... for all the good info on finding 3cx800 tubes. These tubes (8874's) are making good power, so I think I will wait until I really NEED to do a conversion. 73 de Steve, NR4M _______________________
What do you get if you spend 31 secs? www.ur4ll.net? 30 seconds with Google gives www.urrll.net 73, ... Joe, W4TV --Original Message-- From: Behiels jean-Pierre Sent: Thursday, January 29, 2015 7:33
Hello all, Took a QRO HF-2500 out of storage and put it on my 40 meter mult station. Tuned by the book (because I never can remember how to tune this thing without the book...) and the output is low
The K3 that is driving it shows 1.2 or 1.3 to 1 standing wave. Steve On 2/20/2015 00:31 , TexasRF@aol.com wrote: 90W drive; how much reflected? 73, K5GW In a message dated 2/19/2015 5:22:23 P.M. Cent
Hi Carl, and others, My apologies for taking so long to get back you everyone on this. 'Life' got in the way. I got the amp moved over to another position and put the output into a dummy load. Drivin
As in open filament? Wouldn't that affect the plate load impedance, tank settings? I once had a hb pair of 4-400's in which one plate lead broke. The one tube was cherry red and meter needles flying
With both rigs the input showed low SWR. 40m on the K3 and 40 and 20m with the Omni. I guess the next thing is to swap out the tubes, one at a time. Steve That amp is notorious for frying input circu