Re: Topband: Series LC to notch AM broadcast ?

On 2/20/2022 9:41 AM, jim.thom jim.t...@telus.net wrote: Has anybody tried using a simple series L-C to notch out ONE offending AM broadcast station ? I'm talking about wiring from hot side of coax...to Jim VE7RF _ See: MFJ-8504AN, AM Notch Filter 73 Rick N6RK

Re: Topband: TV coax + F-connectors

On 2/20/2022 7:46 AM, Radio KH6O wrote: Reading the comments about possible lack of uniform impedance and other short-comings, I remind myself that I'm an amateur, not a professional. A few milliwatts loss doesn't concern me. 73, Jeff KH6O _ The issue of non-uniform

Re: Topband: Series LC to notch AM broadcast ?

The secret to using this sort of solution is to apply just enough of it to kill off the mixing products that are the result.  The good news is that you get (generally speaking) a 3:1 payback - so 1 db attenuation of the BC station will knock the mixing product down by 3 dB.  So 45 dB (as the

Re: Topband: Series LC to notch AM broadcast ?

We had a 1550khz in town and a 1450khz moved 2 blocks away from 1550. Yep mix products on 1650khz and 1350khz. ( and to some extent 1500khz ) a simple 1550 notch on the top of the 1450 transmitter eliminated the mix products and didn't bother the 1450 transmitter. Don W4DNR On

Re: Topband: Series LC to notch AM broadcast ?

On 2/20/2022 3:33 PM, Grant Saviers wrote: Somewhat related was my effort to produce a pair of 80m notches so CW and SSB could run 80m simultaneously on Field Day (separate antennas). While the CW guys would be ok with 20KHz BW, not so for the SSB team. Just below a Rx 40db notch was about the

Re: Topband: Series LC to notch AM broadcast ?

>>HP filters offer little rejection towards the top end of the AM broadcast band. like 1200-1710 khz. << I built several HP filters with >40 db attenuation on 1.7 KHz based on QST, I don't remember the year 90's about it. But some good information here >

Re: Topband: Series LC to notch AM broadcast ?

Being the simplistic cheapskate that I am, I got rid of all my AM IMD with a 2k pot in the receive line. :-) Tip from W8JI about 40 years ago. Just attenuate everything. Works for me. 73 Mike W0BTU On Sun, Feb 20, 2022 at 11:42 AM jim.thom jim.t...@telus.net < jim.t...@telus.net> wrote: > Has

Re: Topband: Series LC to notch AM broadcast ?

Somewhat related was my effort to produce a pair of 80m notches so CW and SSB could run 80m simultaneously on Field Day (separate antennas). While the CW guys would be ok with 20KHz BW, not so for the SSB team. Just below a Rx 40db notch was about the best I could do with a one db loss Tx.

Re: Topband: TV coax + F-connectors

On Sun, Feb 20, 2022, 2:55 PM Jim Brown wrote: > On 2/20/2022 10:53 AM, Mike Waters wrote: > > And RG-6 has a power handling curve very similar to RG-213. > > WRONG! This may be true of SOME RG6 cables, but definitely NOT true of > many. > Point well taken, Jim! I actually use a couple

Re: Topband: Array of MiniWhips?

Hello Ash, It depends on how complex an array you want to build as to whether these amps would work OK. Two or three elements might work fine. There are several things that concern me about these amps. I do not have the time to test them here however. First there is no way to make

Re: Topband: TV coax + F-connectors

On 2/20/2022 10:53 AM, Mike Waters wrote: And RG-6 has a power handling curve very similar to RG-213. WRONG! This may be true of SOME RG6 cables, but definitely NOT true of many. For at least 50 years, RG numbers have not been a spec, but rather a general description defining impedance and

Re: Topband: Series LC to notch AM broadcast ?

On 2/20/2022 9:41 AM, jim.thom jim.t...@telus.net wrote: Has anybody tried using a simple series L-C to notch out ONE offending AM broadcast station ? Sure -- although I don't remember doing it, I knew about it almost from when I was first licensed 65 years ago. 73, Jim K9YC

Re: Topband: Array of MiniWhips?

Hi Steve, Thanks for your email and information. We've been looking at the preamp design again but didn't manage to confirm if it would deliver accurate phase/amplitude. Can you (or anyone here) check the design and advise. It can be found here: http://www.kiwisdr.com/docs/pa0rdt_whip.pdf

Re: Topband: TV coax + F-connectors

I can testify that F connectors with RG-6 will handle the legal limit on at least 160 and 80 without even getting warm. This is true here with 2500 watts into a dummy load and CW contesting. I waterproof mine by partially filling them with silicone dielectric grease. Been doing that here for

Re: Topband: Series LC to notch AM broadcast ?

Hello Jim, Better, I think, is this notch, found at the IRCA Reprints: https://www.ircaonline.org/editor_upload/File/reprints/irca-reprint-index.pdf Look for Reprint A-063, An RF Notch Filter by VE6JY. You

Re: Topband: Series LC to notch AM broadcast ?

I will try if you are or anyone is interested getting the design of this filter we use on a AM radio broadcast antenna when we use it on 160 Meters. This is NOT just a matching unit to match the antenna for us to use on 160 meters. BUT also a pass band filter for 160, a High pass filter

Topband: Series LC to notch AM broadcast ?

Has anybody tried using a simple series L-C to notch out ONE offending AM broadcast station ? I'm talking about wiring from hot side of coax...to chassis / groundlike via a T connector etc. On paper, it should work. Did some minor research, and one comment was that by using higher values of

Re: Topband: TV coax + F-connectors

Greetings. I do not know if they still do use them. But the MAJOR Amateur AND PROFESSIONAL antenna maker M Squared uses "F" connectors in their antennas ALL the time. They even use a variation that is weatherproof. They use them from below 1 meg antennas up to antennas in the Gig ranges.

Topband: TV coax + F-connectors

Colleagues, I was very happy to see the discussion regarding the use of television feedline and F-connectors. I thought I was the only ham in the universe using that combination. While it's true that the connectors are not weather-resistance, a coating of black asphalt sealant* takes care of