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Messages - KE7TRP

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1
Amplifiers (QRO) / SB220
« on: April 30, 2014, 09:01:00 AM »
Bird 43.
FT101 at 100 watts
FT101 At 145 watts
SB220 at 1000 watts
SB220 at 1450 watts


2
AM Transmitters / Re: Johnson Pacemaker
« on: March 12, 2014, 04:42:15 PM »
More pics

3
AM Transmitters / Johnson Pacemaker
« on: March 12, 2014, 04:38:49 PM »
Some pictures of my Johnson pacemaker.

4
WANTED / WANTED. 4 Pin Johnson BIAS plug.
« on: November 28, 2013, 10:34:38 AM »
I looking for this 4 pin plug for my Pacemaker. Thank you for any help locating one.

C


5
AM Transmitters / Re: WA2ROC Studio A
« on: November 27, 2013, 07:19:55 PM »
That's a score!  Never thought about looking for the clock in a different radio like that.

C

6
Antennas / Multi wire 80 meter dipole plots
« on: August 15, 2013, 02:04:25 PM »
My friend ran some data on an 80 meter dipole.  The idea is NOT to cover the entire 75 and 80 meter band. The idea here is to cover EITHER,80 meters OR 75 meters with no tuner.

This would be a coax fed antenna, at 45 ft high in an inverted V setup.   I will try adding one more wire to my existing 80 meter dipole when the weather cools down. Its 110F outside currently.  In the real world my 80 meter single wire dipole with DX engineering balun has 200KHZ under 2 to 1.  More than the plot shows for a single wire dipole.  I suspect that with one extra wire attached using Ladder snaps will likely get me the entire 75 meter band under 1.5. 

Ke7TRP

7
AM Transmitters / Re: WA2ROC Studio A
« on: August 14, 2013, 08:52:33 AM »
Looks really nice!  I had a friend who had one with the clock in it. The clock even worked. I will ask around for you.

C

8
Antennas / SWR bandwidth data for 40 and 80 meter Inverted V
« on: August 12, 2013, 11:26:02 AM »
My latest antenna project is a DX engineering 10K+ 1 to 1 Current balun with wires for 40 and 80 meters. I am very pleased with the performance of the antenna so far. I would like to increase the bandwidth of 80.  I might try larger size wire to see if that helps.  I am currently using 14AWG wire.


The data was captured from the AIM4170C.  I wasted a week of testing and tuning the 80 meter antenna because the MFJ259B was reporting a 1.9 to 1 SWR for this antenna.  After noticing that the radio was showing 1.2 to 1, I asked my friend to bring his AIM over. 

The first file is the data for the 40 meter band.

The second two files are the same antenna on 80 meters.  One file is for 100Ft of feedline. The other plot is with another 100Ft of feedline added in for a total of 200Ft.


The setup:

55ft crank up tower up about 45 ft.
DX ENG 10K+ 1 to 1 current balun mounted on horizontal fiberglass arm
Two wires for 40 and two for 80 spead out 45 degrees forming a bow tie.



9
Receivers / Re: Pictures of some of my recievers
« on: August 10, 2013, 05:20:55 PM »
Yes. Jim. That is an R390.  I had a Collins R390A and a R390.

C

10
Antennas / Re: Double Bazooka antenna plans
« on: August 04, 2013, 01:05:36 PM »
I have a problem with SWR on the 80 meter DBZ.  I had it tuned very flat.  I then installed it on a Fiberglass Arm of the top of the tower,  Now the minimum SWR is 1.8 to 1.  I swapped feedlines with no change.  I moved the legs around with little change. 

I had this same antenna and feedline pulled up the tower with rope and pulley to the same hight and the match was low. Now its high.  I have exhausted Ideas for now. 


11
Antennas / Re: 40 meter Double Bazooka Vs 80 meter ladder line fed doublet
« on: August 04, 2013, 08:17:48 AM »
Yes. Over the last few years the noise in the neighborhood has increased to the point where I looked for another antenna.

I took the tower down yesterday.  I put the 40 DBZ north and sound one section down from the top.  The top holds the 80 DBZ east and west.    This way they are 10 ft apart and 90 degrees. 

One of us taped the beams coax to the second section when we taped up the coax for the 40DBZ. So when I cranked the tower up today, it ripped the coax connector out of the lead that runs to the Mosely beam.  ARRRGH!  I got the tower all cranked up, secured and ready to get on the air, had no RX on the beam, Walked outside and found the coax dangling 60 ft in the air. 

After I cool off, I will have to take the entire tower back down and repair it.
C

12
General discussion (QSO) / Re: FM Beginnings
« on: August 03, 2013, 12:09:13 PM »
Its really a sad story.  Of course, Many believe that someone through him out the window. We will probably never know.

C

13
Antennas / Re: 40 meter Double Bazooka Vs 80 meter ladder line fed doublet
« on: August 03, 2013, 12:04:41 PM »
I did some more testing.   I used glSDR application on my Android smart phone to access SDR receivers all over the world and US.   glSDR has a full band scope and water fall display.  I sent out a signal using my Call Sign on open frequencies and tuned the Remote receivers to match. In most cases the 40 DBZ is the same as the Open wire line doublet.  I don't see much difference , Sometimes there is a few DB higher on the DBZ. But for the most part it is a wash. I attempted to access each 360 degrees from my station. Since I am south west, This is difficult, However, I do not see any real difference broadside to end fire. I think this is because the antennas are pretty low on the nested tower.  I am really enjoying the significant decrease in noise with the DBZ and the lack of feedline radiation and interference over electronics.

14
Antennas / Re: Double Bazooka antenna plans
« on: August 03, 2013, 12:04:26 PM »
Yes. Performance is very close. This was a surprise as the open wire line antenna is a double on 40 and has some slight gain. 

I am really enjoying the lower noise floor and lack of noise.  The signals are slightly higher on RX and weak signal is far better.

The RG11 is much lighter coax and it Is 75 ohms and that really helps when you run full size coax like this from a weight standpoint.  When the weather cools off, I will try some RG8U and see if the bandwidth increases.  For me, I don't mine walking out to the yard and unfolding the ends of the antenna to work 80 meters.  It takes about 5 minutes and I take the golden retriever out back all the time anyways.

15
AM Transmitters / P&H Audio compressor AFC-2 REHAB
« on: July 30, 2013, 05:36:04 PM »
I got this sweet P&H vintage Tube audio compressor recently and plan to rehab it this weekend.  The AFC2 was made in the 50s for ham radio use.  It features an AVC compressor and selectable Audio bandpass filters.  A neat feature of the AFC2 is that it has LOW and HIGH impedance inputs and outputs. So you can use any combination of low or high microphonium and low or high OutPOOt. 

Here are the pics as received.  I removed the tubes and ordered the capacitors so far.  I will replace the caps and install a 3 wire power cord. I also plan to clean the AFC2 to like new condition.

I will likely use this with a vintage EV664 mic and then into the Johnson 500 transmitter.

C

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