To: | "[email protected]" <[email protected]> |
---|---|
Subject: | Re: LF: A/G FREQS |
From: | julie <[email protected]> |
Date: | Tue, 26 Jun 2012 22:19:29 +0100 (BST) |
Dkim-signature: | v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1340745569; bh=jXd2ZuWs7SvmTdQKXSLpYNpLBoiqP5eS2fAW+A5Uuto=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=g0jNKNCr+B5A6HYPYzDiglFTBSxE709WzhXNtO+S5bzuIxDlgzRugFPVYFwR2MTE1RIV8R1iXSHQjgGtUqp4RYe0/QMEpG44t67fdS9iT0TQ/cRFkY602nxso281bzVU82lR+FmTZAPqkBlRTBqtkw5dNMlX196DPMqdIhslOrM= |
Domainkey-signature: | a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=CiJtgU5JPG2BGxVLLN9B3x0z5Q8itGtRMvI6V+iRqYoUcRBiPRYF3/wYL8fhHdFNIxKYHOyWiIVlBP0eJkaxt8/DGsIrf+zEjFDUDhrLjklv+0jwE4snLX57KM0NP6w9jg+HjcZ6fBXpQQ4uaUN8b4GU2Qb6sOzC1qBxquvDGZ4=; |
In-reply-to: | <[email protected]> |
References: | <002801cd536e$76b08400$0401a8c0@xphd97xgq27nyf> <172D1CB5F32F43A790DBC99A73F73D59@AGB>,<[email protected]> <[email protected]> |
Reply-to: | [email protected] |
Sender: | [email protected] |
Hi can any one give me some advice on how to fill out ofcoms nov, i am a bit stuck.
David G6WGZ
From: Gary G4WGT <[email protected]> To: LF Group <[email protected]> Sent: Tuesday, 26 June 2012, 18:51 Subject: RE: LF: A/G FREQS Hi All, Pete M0FMT wrote :- When I were a Jate we only had one xtal and a QQV02-6 on 432.00 amplitude modulated on the plate in the good old days. That was my very first transmitter.....And don't forget...."Tuning high to low for a reply". That takes me back :-) 73, Gary - G4WGT.
Date: Tue, 26 Jun 2012 17:42:37 +0100 From: [email protected] To: [email protected] Subject: Re: LF: A/G FREQS Well Graham when I were a Jate we only had one xtal and a QQV02-6 on 432.00 amplitude modulated on the plate in the good old days. After all its just the product of mixing two frequencies 432 with audio in a nonlinear device like a Class C amp works from almost DC to light!. Nowerdays I guess you would PWM the carrier on the PA gate/ base producing the same effect and using considerably less power over all. Class E an all.
73 es GL Pete M0FMT IO91UX
From: Graham <[email protected]> To: [email protected] Sent: Tuesday, 26 June 2012, 17:09 Subject: Re: LF: A/G FREQS Steady on Mal ! this is getting technical !"
Your right , FM has a cut off point , where demodulation fails and also a capture effect , where the stronger of 2 signals will acquire and hold the demodulator ..always fun on 2 mtrs when a mobile suddenly takes the channel
Am has no cut off point , but gradual degradation until the recovered audio is no longer usable ......eg, mcw would readable much lower than AM speech
I think much over 250/300 MHz its actually not possible to produce AM , could be wrong , but there is a limit , may be by high level modulation falls over , dont see why could not be via transverting .......
G..
As stated Air/Ground vhf/uhf is AM and simplex working. I have also noticed a well modulated AM transmitter is more potent than a FM transmitter when working at max range. On AM the RX bandwidth can be opened up to receive several stations simultaneously then select the one of interest by closing down the selectivity, the same applies on CW. On FM if you tried this the transmission would fall into a black hole, in other words the FM rx has to be tailored to the exact bandwidth of the transmission (same deviation value)
g3kev
|
<Prev in Thread] | Current Thread | [Next in Thread> |
---|---|---|
|
Previous by Date: | LF: oz7foc, mal hamilton |
---|---|
Next by Date: | Re: LF: My SAQ monitor here..., PA1SDB, Peter |
Previous by Thread: | RE: LF: A/G FREQS, Gary G4WGT |
Next by Thread: | Re: LF: A/G FREQS, Roger Lapthorn |
Indexes: | [Date] [Thread] [Top] [All Lists] |