Recent content by QRP 725

I forgot to mention I'm will be using a wire lead to tap onto the coil. Like a mobile HAM multi band antenna uses for adjusting for different bands. Just to experiment, I will make my coil and also use the exact length to make a second unraveled tuning part in a u or circle shape. I will...

Thank you for taking the time to help me. I've had made quads, delta loops, EFHW, yagis, moxons using gamma, hairpin (beta), baluns and ununs with great success. I do think the coil design has more to do with the magnetic field as the main differance. I highly recommend a RigExpert antenna...

I'm making a 5/8 wave vertical antenna. I understand that inductance matching with a coil lowers the impedance of a 5/8 wave that I believe is about 250 Ohms. Is the coil design using its magnetic field to create inductance as its main purpose? Or is the coil just using its length to...

Thank you!!!

My Cobra 148 GTL (Philippines), IC3 (AN612) pin 7 is showing 7.6 volts. I'm trying to do an alignment and checked for voltage before connecting my BK 1803D freq counter. The max input for the counter is 3 volts. I thought that pin should be 2.8 volts? I did notice R131 was cut, so I put a new...

What toroid mix? Thanks for posting this design.

Thank you Andy. I will use the 810/465.

Does anyone know the what the PC-122 bias adjustments should be set to? I do not have a service manual. I noticed the similar radios like the TRC-453 and Uniden 810 have different values. Where is a good source for authentic 2SC2312C and 2SC2166 transistors? Thanks.

I do agree it is best to have it done correctly. I had a feeling the way I was doing was wrong. It was to easy lol! Thank you for your help.

On LSB some of the locals told me I was off. Yes I waited an hour for it to warm up. I plan on just sending the radios to a repair shop to have it done properly. I was just hoping what I did would work. There are not any repair shops where I live. I will pack things up and mail them to a shop.

Robb, I do know that the 8 digit is far better. I did read the Service Manual for each radio. That is how I learned of VR5 in my Cobra 148. If I sound good while on SSB on a second receiver and others say I sound fine, isn't that acceptable? I'm not a tech for sure and never will be. This...

I have a question about adjusting the transmit frequency for a Cobra 148 and Realistic TRC-451. My radios were off frequency, so I adjusted the transmit frequency potentiometer in each radio. For example VR3 in the Realistic. I only have a 5 digit frequency counter, and used that while...