Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - KE7TRP

Pages: [1]
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 / Johnson Pacemaker
« on: March 12, 2014, 04:38:49 PM »
Some pictures of my Johnson pacemaker.

3
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


4
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

5
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.



6
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

7
Antennas / 40 meter Double Bazooka Vs 80 meter ladder line fed doublet
« on: July 28, 2013, 11:58:26 AM »
This test is a 40 meter Double Bazooka wire antenna made from RG11 coax VS an 80 meter open wire line doublet.  The Doublet is from Trueladderline.com and uses 600 ohm feedline. The antenna is hooked to a Johnson KW matchbox balanced tuner. The Doublet is at 40 ft.  The Double bazooka is at 30 ft.  The DBZ has a lot less noise with stronger signal than the Doublet.


I took this video today.

http://youtu.be/_nWCGKyOSqk


8
General discussion (QSO) / A tour of WLW 500,000 watt AM radio station from the mid 1930s
« on: July 21, 2013, 01:28:45 PM »
http://www.youtube.com/watch?v=CbHjcwIoTiY

Enjoy!

9
General discussion (QSO) / HAARP shuts down
« on: July 21, 2013, 12:39:43 PM »
No more HAARP.  Article from ARRL:


http://www.arrl.org/news/haarp-facility-shuts-down

10
Antennas / Double Bazooka antenna plans
« on: July 09, 2013, 08:38:01 PM »
I just got this info from a friend of mine. They built this antenna and he said it does cover the entire 80 meter band under 2 to 1.  His signal is stronger then his old wire and he no longer needs the tuner.  I thought I would post this info up in case there are any other antenna experimenters out there.

C

11
Antennas / 40 and 80 meter wire dipoles... How far apart?
« on: July 06, 2013, 04:05:04 PM »
I am thinking of trying a few different options for 40 and 80. 

I was thinking of trying out the 80 meter Double bazooka.  Mainly because it will cover a wide bandwidth. This antenna will be mounted from a fiberglass arm off the top of the 55 ft crank up tower and set up as an inverted V.

For 40,  I was thinking of making a standard dipole or another bazooka but then hanging this antenna off a side arm from the middle section of the crank up tower. 

Two dipoles, on the same tower.  One at the top and one at the top of the middle section. 

The distance apart would be 6ft when tower is cranked down for summer and 15 to 20 ft apart when the tower is up all the way. 

I have never ran two dipoles this close.  Will this work out ok since the two are on different bands.

Is there any real reason, I cant put both separate antennas on the top of the tower?   The 40 wires would run out and be tied off away from the 80 wires.  Kind of like a fan dipole but with two Bazookas and two coax lines.

Thanks for any thoughts on the subject!

C


12
AM Transmitters / Transmitter pictures.
« on: June 10, 2013, 03:56:47 PM »
Here are some pics of transmitters that I own or have owned over the years.

13
Receivers / Pictures of some of my recievers
« on: June 05, 2013, 10:16:11 AM »
Some pictures of my receivers.

14
AM Transmitters / Eimacs 1947 Handbook "Build your own transmitter"
« on: June 05, 2013, 08:07:05 AM »
Really cool 1947 handbook featuring the 4-125, 100TH, and my favorite the 450TH.

Enjoy!

15
Software Defined radio (SDR) Forum / Soft66LC2 SDR as band scope with FT2000
« on: June 04, 2013, 02:35:14 PM »
Here is a video showing my SDR setup.  I use my SDR in two ways.

1.  The Soft66LC2 looks at the Heros Technology up converter.  This converter is hooked to the IF output jack (455KC) of my Collins R390 receiver.  The Heros, then outputs 4.455 which is hooked to the SDR input.  Once the SDR is tuned to 4.455, I can then see the IF of the R390.  The Heros is not cheap but it is very low noise.  This makes for the ultimate HiFi reciever.  Collins R390 front end to the SDR.  I can knotch out any signal and set the bandwidth real time.

2.  The Soft66LC2 is hooked to the RF-space, IF2000 card that installed into my Yaesu FT-2000.  This provides a bandscope/third reciever. I normaly set the Scope at 100 KC wide so I can view nearby signals and spot DX traffic. The SDR tunes bi-directional with the FT2000. That is if you turn the VFO on the 2000, the SDR follows,  If you tune the SDR radio by mouse clicking on HDSDR software, the FT2000 follows.

Here is a short video I took when I was setting up the SDR.  I know have the software on shack PC with a 21.5 inch flat panel monitor over the FT2000.  The laptop was used for testing.

http://www.youtube.com/watch?v=78iF5_-XNcg&feature=share&list=UUqyZ7V9qQcpVYtDMy3CSz4g


Pages: [1]