My biggest  concern would be to make sure the homeopathy was not interfering with my RF.

Dale W4OP

I admit - it's a mess and a far cry from the honorable hams of yesteryear.

Dale W4OP

I have steered away from this rig- but have you taken into account the BFO or sideband offset frequency?
1.5KHz is very common but maybe 1.2 KHz is used in the Bitx

Dale W4OP

You can see my version of the Accu-Keyer in photo #17.
http://www.parelectronics.com/par-homebrew-projects.php

I built this for my Mom many years ago. It's now a 'hanger queen' but still works FB.
I think I may have spare 2102 memory chips.
Dale W4OP

Well, if the competition is sleazy, and in this case there is no doubt, then Don is doing all a favor, agreed?

Dale W4OP

The balun issue for receiving is  a bit different. For HF receive, our noise floor is not limited by the receiver front end noise as it is on VHF and up. At HF, the limiting factor is :
1.Man made noise
2. Galactic Noise
3. Atmospheric noise

You can easily prove this by tuning your receiver to a dead portion of the lower HF band and removing your antenna- the noise floor will drop.

With that said then, antenna efficiency means little for HF receiving. Loss because of lossy coax, reflection loss etc does not change the signal to noise ratio at the receiver because signal and noise are both attenuated equally.

So does a balun help? The answer is yes, because without it, the outside shield of your feedline becomes part of your antenna. It will pick up noise from all the noise sources in your home, transfer that noise on the outside of the shield (remember, because of skin depth, the outside  surface of the shield is electrically separate from the inside) to the antenna where that noise is picked up and brought back to your receiver on the inside of your coax (differential mode).

So, you may have worked very hard to locate your antenna away from your house, only to have that low noise location compromised by common mode noise.

The other issue of course is that because the coax w/o a balun is now part of your antenna, it will alter the pattern of your dipole, beam etc.

Dale W4OP

Usually a 160M antenna is a horrible match for 80M. eg, a half wave dipole on 160M would be a voltage fed antenna on 80M with a huge VSWR. Same for a quarter wave vertical or an inverted L. I can only imagine how loud the harmonics would be if the offending station were running say a 160/80 fan dipole.

Don't think my K3 was overloading......

Dale W4OP

Thanks Greg. I was looking at their catalog last night and w/o having the gear to look at, I believe it is a 20 degree gear with a 32 pitch/ 1.5" diameter and 48 teeth. Another ham is going to send me a pix of that area of the VFO. If I buy one, I guess I'll need two and have to mill slots for the backlash springs.

Once I confirm the gear- I might be able to find some cheap in the hobby area of eBay- model cars etc. Small Parts want around $20/gear

The real shame is that I sold an NCX-5 parts rig a couple years ago. Lesson learned- never sell anything.

Tnx,

Dale w4OP

I copied perhaps 15-20 160M CW stations on 80 m during the contest. Running a K3 with narrow roofing filters.

Used to hear the same when I had my Icom 7700. I hear the same from my 75M friends. Everyone in the group copies them.
Dale W4OP

Long shot- but I am looking  for the antibacklash spur gear on the main tuning cap of the VFO.
Tnx,
Dale W4OP

The K-40 base is a series coil and capacitor to ground. The coax is tapped across the cap and ground.

Dale W4OP

Have you looked at Jim Hagerty'y DDS? I see he now has bandswitch input and you could likely use his DDS and this board  to control your filters:
http://www.wa1ffl.com/rotaryVFOcontrol.html

Let us know how you progress.
Dale W4OP

The simplest solution would be to end feed the half wave wire with  either a tapped L-C or an L network. That way, the antenna is 1/4 lambda shorter, lighter and you are not concerned with getting the radiator length, stub length and feedpoint all correct.
You can even make the TX PA output  a high impedance and do away with the matching network that an end fed half wave would otherwise require.

Be cautious though- just because  the rocket tube may be non-conductive, tells little about what it looks like to VHF or UHF RF.
Design the antenna and then temporarily stick it to the tube and see how the properties shift.

Dale w4OP

Instead of modifying a nice BA, why not build transverters?

Dale W4OP

Again, the overriding question is why do people continue to buy from a guy like this?
There are hundreds of horror stories on the internet.

Dale W4OP