Once again, you are referring to another thread.
We do not disagree on the sound of his receiver.
I live in Holland. I'm well aware of people sounding like ducks
Here, we were discussing carrier suppression and the benefits of SSB. I felt the discussion needed to be clarified as to what was being meant by quality of sound (or voice) and designing so that voice can best be heard through a very noisy environment.
That is all, over and out. 73s old man. QRT
Sorry Varmint, it does sound much worse than necessary.
Lots of distortion. Do you have access to an RF signal generator?
Audio generator? Scope?
"The problem is, I want to adjust for upper and lower sideband using one crystal but don't think I can warp it that far.
What is the recommended difference frequency again? It's like 15K apt it?"
If I understand what you are asking, you want the carrier 2k from the filter or a little less.
I don't remember your IF freq. but below 1mhz, you won't be able to pull the xtal even 1kHz, I think. I have wondered if a ceramic resonator would be good for this but have not researched it.
Edit: not sure you could call this research, but I found this right away.
**broken link removed**
more info:
**broken link removed**
data sheet:
https://www.electro-tech-online.com/custompdfs/2008/12/p16e9-1.pdf
Once more:
VFO with Ceramic Resonator
Oscillators
Simple Modular DSB TX:
**broken link removed**
High speech frequencies don't use much power. They use bandwidth.Oh that's just silly. AM radio often has a bandwidth of 6khz.
Can you still hear out to 14khz? I don't think I can.
(What did you say?)
He is designing a ham band receiver. It has a special purpose.
The transmitters he is listening to are not wasting power on high and low audio frequencies. Bell labs decided many years ago that 300-3k would get the job done and they were right.
If a ham receiver produced 300Hz to 3kHz with low distortion then it would sound a lot better than the extremely narrow bandwidth and high distortion from The Varmint's radio.
The radio under discussion is so badly designed it's going to perform badly and sound terrible - but good 'quality' 300Hz to 3KHz is all you need for good speech communication. It's all about low bandwidth and communicating across large distances, under poor conditions, on relatively little power.
Here is an excerpt from Audels Radiomans Guide 1939 reprint 1945. It talks about speech bandwidth. I hope some find it interesting.
BTW, quite a few old radio texts, mostly books on tube circuits and design but also including the ARRL Handbooks for 1936 and 1940 and a few of Orr's Handbooks are downloadable at the site. Show interest and I'll post the link. Copyright long gone on these books.
Sorry Spaceman, not too many of the circuits will be useful in your current project
I just found the info interesting. Speech bandwidth is one of the topics this thread is about, indirectly...as in filter bandwidth and bfo/filter freq. offset. I also thought you might like to check out the page. Lots of old radio books in PDF.
Most important in the bal. modulator is matching of components in port impedances, and injection level...your talking about transmitter not receiver. I guess it might help to shape the audio before the modulator, yes. Depends how you shape it, your choices.
Did you understand my question about using an attenuator after the crystal filter? What few schematics I could muster up, I found a guy using that technique, I believe to reduce any signal being passed to the amplifiers that isn't actual audio derived energy.
Aaron's site is interesting. I have plenty to learn before I tackle a PLL design. I'm trying to get practical knowledge of toroids for now. 30 years ago I built a good 80 & 40 meter ssb receiver.
I'm starting the hobby again. Just starting to collect parts.
I want to build a receiver again.
The site with the old books won't help you with what you're doing. It would only distract you, or not.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?