Questions tagged [diy]
Questions dealing with handmade (Do It Yourself) radios and radio accessories.
7
questions with no upvoted or accepted answers
6
votes
0
answers
266
views
How to estimate input and output impedance of an amplifier?
I'm trying to figure out how to design power amplifiers which input and output are properly matched to 50 Ohm. My thinking was that the most bullet proofed approach would be to model an amplifier in ...
5
votes
0
answers
605
views
What is an expected IF level of SA612?
I tried to use SA612 as a frequency mixer. Since it's a Gilbert cell, it has a high input impedance. Thus I added a pair of transformers as "Experimental Methods in RF Design" book suggests:
...
4
votes
0
answers
152
views
Problem with theory of HF detector
I'm currently trying to build my own SWR power Meter. This design is based on the so known HT detector with schottky diode BAS70. For my understanding, and for easy purpose, I'm currently focusing on ...
2
votes
0
answers
82
views
IF derived AGC: how to choose the best block diagram?
I've built several transceivers in the past. I never implemented IF derived AGC, so I decided to give it a try in the next project.
I choose to build a superheterodyne receiver, which will probably ...
2
votes
0
answers
113
views
Has this regeneration control been done?
I'm planning to build a two-tube reflexed RF regen receiver soon. I'm examining methods of controlling the regeneration — it needs to be possible to both initiate and halt oscillation in all bands (I ...
1
vote
0
answers
58
views
How do I test if three turns are better than 4 turns?
I built a class ab amplifier kit to use with my qrp radio. 2 watts in creates 50+ out.
This was the pa 70 amplifier kit.
It is a kit with no instructions, but a whole suite of internet videos and ...
0
votes
1
answer
40
views
Gift for a dad who used to be an amateur radio nerd
We're going on a 2 camper trip to canada this summer and my sisters suggested getting him walkie talkies to talk between them for his birthday.
Now I know my dad used to love messing around with ...