[Drakelist] MS 4 speaker-Drake trivia
Hi, I have an older ms-4 that came with an early R4a I recently acquired. Interestingly, it has a speaker with an alnico magnet. My newer Ms-4, that is R4C vintage, has a ceramic magnet. Doing an A/B of the two, I think the alnico model sounds better, which is what I would have suspected. Any comments here? Can I assume the alnico is original? Any idea when Drake switched? Thanks, David Wd9cmd___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] VFO for 2NT
Hi all, If I were building a VFO for a 2NT, what would be my frequency range for the output to plug it into the crystal socket on the front? Thanks, Bill, WB9CAC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] VFO for 2NT
Hi Bill, I am sure someone will come up with a manual, I don't have one. It would appear that the VFO frequency output should be the same as the fundamental frequency of whatever crystals are required buy the manufacturer. The only thing you will have to watch is the amplitude of the output from the VFO. 73 and good luck, John, W4AWM **From Wall Street to Main Street and everywhere in between, stay up-to-date with the latest news. (http://aol.com?ncid=emlcntaolcom0023) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] VFO for 2NT
From the 2NT Manual: 80 meters Crystal X 1 3.5 - 3.8mhz 40 meters: Crystal X 1 7.0 to 7.2 20 meters: Crystal X 2 7.0 to 7.125 15 meters Crystal X 3 7.0 to 7.083 10 meters Crystal X 4 7.0 to 7.125 So, looke like 7 to 7.2 gets you everything BUT 80 meters on this radio. Bill Ellis wrote: Hi all, If I were building a VFO for a 2NT, what would be my frequency range for the output to plug it into the crystal socket on the front? Thanks, Bill, WB9CAC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] VFO for 2NT
Bill -- there is an addendum page for the 2NT manual that gives you the frequency ranges and drive levels required; I'm sending that to you direct as I'm not sure it'll make it thru the mail list. I've used the Norcal FCC-1/2 DDS VFO/counter to drive the 2NT. The DDS board puts out enough to drive the rig on 80/40m since the rig only requires about 1V RMS of drive (3.5 Mhz and 7 MHz respectively); for 20m and above it takes 4/12/4V RMS respectively at 7 MHz. Although I have yet to try it here's a suggestion from W3CD that I got a while back on how to step up the drive from the VFO to perhaps meet the higher drive requirements: From: Bob Okas vinta...@earthlink.net Date: April 17, 2008 2:55:16 PM EDT To: 'Dino Papas' k...@cox.net Subject: RE: Using the FCC-1/2 with a Tube Type Transmitter Greetings Dino, The matching network is a simple L-network that matches the 50 Ohm output impedance of the FCC-2 to a higher impedance transmitter input. The inductor is in series with the FCC-2 output and the cap shunts the TX side of the network. The trick is determining what the 2-NT’s input impedance is. A good starting point is to guess around 1K. The network will offer roughly a 20x voltage step-up, which should be adequate to drive the TC on the higher bands. To determine what component values to use for the L-network, look at: http://bwrc.eecs.berkeley.edu/Research/RF/projects/60GHz/matching/ ImpMatch.html Use a Q value of 7 and you should get some reasonable values. 73, Bob – W3CD Hope this helps. 73 -- Dino KL0S ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] VFO for 2NT
Bill, page 9 of the 2NT Manual says 80m crystal 3.5MHz to 3.8MHz Output Freq 3.5MHz to 3.8MHz 40m crystal 7.0MHZ to 7.2MHzOutput Freq 7.0MHz to 7.2MHz 20m crystal 7.0MHZ to 7.125MHzOutput Freq 14.0 to 14.25Mhz 15m crystal 7.0MHZ to 7.083MHzOutput Freq 21.0 to 21.25Mhz 10m crystal 7.0MHZ to 7.125MHzOutput Freq 28.0 to 28.50Mhz So, if your VFO covers 80m and 40m you will do it. Yes you will need to make sure you do not overload the 6EA8. Also if your VFO cover the fundamental frequency of 20/15/10m it will ork as wel. Regards Fred PY2XB On Sun, 25 Jan 2009 16:27:21 -0200, Bill Ellis wrote: Hi all, If I were building a VFO for a 2NT, what would be my frequency range for the output to plug it into the crystal socket on the front? Thanks, Bill, WB9CAC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] VFO for 2NT
Some observations: It appears the 2NT is using harmonics of the fundamental for 20m, 15m, and 10m. With a VFO, I expect it would have to be designed to provide these harmonics or the actual fundamental frequencies. For harmonics, they would have to be of the appropriate amplitude, and I imagine there would also have to be a fairly reasonable low-pass filter to make sure unwanted harmonics were attenuated. Just some thoughts... 73 - Mark N1VQW ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
