You are right, I didn’t remember, but we don’t need to go far to see this.
If I correctly understood, the R-390A meter itself is calibrated in DBuV. > Il giorno 25 ott 2024, alle ore 02:41, Bob kb8tq <kb...@n1k.org> ha scritto: > > Hi > > You can indeed find standard measures like: > > db V = db above / below one volt > > https://www.everythingrf.com/community/what-is-dbv#:~:text=dBV%20or%20decibel%20Volt%20is,a%20voltage%20below%201%20V. > > db uV = db above / below one microvolt (and milivolt and …. ) > > The cable TV folks like voltage based measurements. There are other areas > that seem to go that way as well. > > Is this mis-use of the term? If so, it’s a *very* commonly accepted mis-use. > > Bob > > > >> On Oct 24, 2024, at 4:05 PM, Ing. Giovanni Becattini via R-390 >> <r-390@mailman.qth.net <mailto:r-390@mailman.qth.net>> wrote: >> >> Thanks! I think I have understood now. As you understood, my mistake was >> thinking that dB could be used for every ratio of congruent values. >> >> Very happy. >> >>> Il giorno 24 ott 2024, alle ore 21:57, Jim Whartenby <old_ra...@aol.com> ha >>> scritto: >>> >>> Gianni >>> >>> Answer to 1 below: dB is defined as a POWER ratio. The use of voltage to >>> calculate dB assumes that the input and output resistances of any >>> electrical system being measured are the same. Take the formula that >>> defined the dB: dB = 10 log (power out / power in). Substitute (voltage^2 >>> /R) for each term "power" then simplify the equation. You should end up >>> with 20 log (voltage out / voltage in). This simplification only works if >>> Rout = Rin. WRT the DA-121, the out resistance does not equal the input >>> resistance or 125 ohms does not equal 50 ohms. So the "voltage" form of >>> the dB equation results in an error in certain cases where the power form >>> never will. >>> >>> >>> Answer to 2 below: you make the point that Rin is 50 ohms and Rout is 125 >>> ohms but then ignore what this means. See Answer 1 above. Also your Ohm's >>> Law calculation for what the R-390 "sees" is in error. (50 in parallel >>> with 68) +100 in parallel with 125 is 63.44 ohms, is it not? >>> >>> >>> Answer to 3 below: the equation you used is wrong, for voltage it is 20 >>> log X not 10 log X so 5 dB would be correct if both input resistance and >>> output resistance are the same but you point this out in your 2 below that >>> they are not equal resistances. Again, see Answer 1 above. >>> >>> >>> Answer to 4 below: you are correct, the loss in the DA-121 is 9 dB when >>> you consider that the input impedance is different from the output >>> impedance and calculate accordingly. >>> >>> >>> Your error is in thinking that there are two different definitions for dB, >>> power and voltage. There is only power, the voltage form of the equation >>> has the caveat that the input resistance must be the same as the output >>> resistance. You are not the first one to make this mistake and surely you >>> will not be the last. >>> >>> >>> Regards, Jim >>> >>> >>> Logic: Method used to arrive at the wrong conclusion, with confidence. >>> Murphy >>> >>> >>> On Thursday, October 24, 2024 at 12:30:03 PM CDT, Ing. Giovanni Becattini >>> <giovanni.becatt...@icloud.com> wrote: >>> >>> >>> Thanks Jim! >>> >>> I try to explain my thought and I would be grateful to whom would tell me >>> at which point I make the mistake. >>> >>> 1.What dB is? For what I studied, dB is just a ratio between two congruent >>> values, so you can define a dB for voltage or for power. >>> >>> 2.DA-121 output voltage. Let’s stop to voltage values for now and work >>> almost in DC, assuming that the R390 has really a 125-ohm impedance. >>> >>> In this case: >>> the generator "sees" 50 ohms impedance (68 ohms parallel to 100+125); >>> the receiver "sees" about 125 ohms (100 ohms + 68 ohms in parallel to 50 >>> ohms). >>> >>> The ratio between the input and the output voltage is easy to calculate >>> just with the ohm law. The output voltage is the input voltage times 0.556. >>> If you don’t want to make calculations see >>> https://ohmslawcalculator.com/voltage-divider-calculator. It’s easy to >>> practically check that this is true. >>> >>> I believe that so far nobody could disagree. >>> >>> 3.Voltage dB value. So, when two voltages has a ratio of 0.556, their >>> ratio, expressed in dB, is 10 log (V1/V2) = -2.5 dB. I am just applying the >>> dB definition (forget 5 dB that was an error of mine). >>> >>> 4.Power dB value. If we want to calculate the power ratio we have (using 1V >>> as input value): >>> >>> P1 = input power = V^2 / R = 1V / 50 ohm =0,02 >>> P2 = output power = 0.556^2 / 125 ohm = 0.0025 >>> >>> So the power ratio in db is 10 log (P1/P2) = -9.078 dB. Again, this is >>> simply the dB definition. >>> >>> Where am I wrong? >>> >>> Thanks for your help. >>> >>> Gianni >>> >>> >>> >>>> Il giorno 24 ott 2024, alle ore 18:08, Jim Whartenby <old_ra...@aol.com> >>>> ha scritto: >>>> >>>> Gianni >>>> >>>> The dB is defined as a measure of the ratio of powers. In electronics, it >>>> is the power output to power input. >>>> >>>> >>>> Using the formula 10 log (Pout / Pin) will always give the correct answer. >>>> This formula considers the resistance of both the input power and output >>>> power separately since power = voltage^2 / resistance. >>>> >>>> The 20 log Vout/Vin will only give the correct answer when both the input >>>> resistance and the output resistance are the same. >>>> >>>> >>>> So the 5 dB calculation using input and output voltage is wrong. In this >>>> particular case the resistance transformation provided by the attenuator >>>> was not considered. If the attenuator did not cause a change in >>>> resistance (the input resistance and output resistance are the same) then >>>> using 20 log (Vout / Vin) would result in the same answer as 10 log (Pout >>>> / Pin). >>>> >>>> >>>> Regards, Jim >>>> >>>> >>>> Logic: Method used to arrive at the wrong conclusion, with confidence. >>>> Murphy >>>> >>>> >>>> On Thursday, October 24, 2024 at 02:26:08 AM CDT, Ing. Giovanni Becattini >>>> via R-390 <r-390@mailman.qth.net> wrote: >>>> >>>> >>>> Hi Guys, >>>> >>>> sorry I was not considered - I hate to be tiring, but an answer would be >>>> great to help me better following the discussion. >>>> >>>> It seems to me that 5 dB in voltage and about 8.9 dB in power are very >>>> easy to demonstrate (keeping out the frequency effect), either >>>> arithmetically, either practically, either with LTSpice. >>>> >>>> At least on this point …. do the parties agree? I could not understand >>>> this. Perhaps, if we don’t agree on this, it is hard to go further. >>>> >>>> No problem if you don’t want to answer...I'm not touchy 😁 >>>> >>>> Gianni >>>> >>>>> Il giorno 24 ott 2024, alle ore 02:18, Barry Scott >>>>> <72volkswa...@gmail.com <mailto:72volkswa...@gmail.com> >>>>> <mailto:72volkswa...@gmail.com>> ha scritto: >>>>> >>>>> GR-1001A. Even funner. >>>>> >>>>> Thanks, >>>>> Barry - N4BUQ >>>>> >>>>> On Wed, Oct 23, 2024 at 4:46 PM Jacques Fortin <jacque...@videotron.ca >>>>> <mailto:jacque...@videotron.ca> <mailto:jacque...@videotron.ca>> wrote: >>>>>> >>>>>> Bob, I see your point, but we know everything about that too ! >>>>>> That's bring me back to the end of the '70s when my workbench signal >>>>>> generator was a Marconi Instruments TF955/5. >>>>>> Output calibrated in Volts EMF (open circuit voltage) and 75 ohms of >>>>>> output impedance ! >>>>>> Using it, you had to compute what was the real load voltage you got all >>>>>> the time... >>>>>> >>>>>> 73, Jacques, VE2JFE in Montreal >>>>>> >>>>>> -----Message d'origine----- >>>>>> De : Bob kb8tq <kb...@n1k.org <mailto:kb...@n1k.org> >>>>>> <mailto:kb...@n1k.org>> >>>>>> Envoyé : 23 octobre 2024 16:49 >>>>>> À : Jacques Fortin <jacque...@videotron.ca >>>>>> <mailto:jacque...@videotron.ca> <mailto:jacque...@videotron.ca>> >>>>>> Cc : Ing. Giovanni Becattini <giovanni.becatt...@icloud.com >>>>>> <mailto:giovanni.becatt...@icloud.com> >>>>>> <mailto:giovanni.becatt...@icloud.com>>; r-390@mailman.qth.net >>>>>> <mailto:r-390@mailman.qth.net>; Larry Haney <larry41...@gmail.com >>>>>> <mailto:larry41...@gmail.com> <mailto:larry41...@gmail.com>> >>>>>> Objet : Re: [R-390] Official specs >>>>>> >>>>>> Hi >>>>>> >>>>>> If you start with a Spice model and put in a 2V source with some series >>>>>> resistance. You loose 6 db when you get to 1.0 V. That’s how Spice looks >>>>>> at things. >>>>>> >>>>>> If you start with the signal generator convention you have a “spice” 2V >>>>>> source and a 50 ohm resistor “inside the box”. Put on a 50 ohm load and >>>>>> you have 1V. That’s your zero db point with the signal generator. >>>>>> >>>>>> Start one way and you are 6 db down. >>>>>> >>>>>> Start the other way and you are at zero db. >>>>>> >>>>>> Bob >>>>>> >>>>>>> On Oct 23, 2024, at 1:03 PM, Jacques Fortin <jacque...@videotron.ca >>>>>>> <mailto:jacque...@videotron.ca> <mailto:jacque...@videotron.ca>> wrote: >>>>>>> >>>>>>> Hello Bob, >>>>>>> >>>>>>> I 100% agree that the convention on a RF source is that the displayed >>>>>>> output voltage is valid only when the SG is loaded with the correct >>>>>>> termination impedance. >>>>>>> I disagree however that the outcome "depends" on what can be used to >>>>>>> provide the answer. >>>>>>> If anyone is ignorant enough to use a Spice model that not include a >>>>>>> source output impedance, it is sure that the result of such >>>>>>> "simulation" will be different from what is obtained with properly set >>>>>>> up test equipment. >>>>>>> A properly used simulation software results will not be different that >>>>>>> what can be obtained with "real" instruments. >>>>>>> If ever this is the case, the inputs to the simulation program are >>>>>>> faulty. >>>>>>> >>>>>>> Bob Pease (RIP) once fell in that trap: he took revenge by throwing his >>>>>>> computer from the top of the building into the parking lot below. >>>>>>> >>>>>>> But, at the end of the day, nothing is more practical than a good >>>>>>> theory. >>>>>>> >>>>>>> 73, Jacques, VE2JFE in Montreal >>>>>>> >>>>>>> -----Message d'origine----- >>>>>>> De : r-390-boun...@mailman.qth.net >>>>>>> <mailto:r-390-boun...@mailman.qth.net> >>>>>>> <mailto:r-390-boun...@mailman.qth.net> <r-390-boun...@mailman.qth.net >>>>>>> <mailto:r-390-boun...@mailman.qth.net> >>>>>>> <mailto:r-390-boun...@mailman.qth.net>> De >>>>>>> la part de Bob Camp Envoyé : 23 octobre 2024 12:26 À : Ing. Giovanni >>>>>>> Becattini <giovanni.becatt...@icloud.com >>>>>>> <mailto:giovanni.becatt...@icloud.com> >>>>>>> <mailto:giovanni.becatt...@icloud.com>> Cc : r-390@mailman.qth.net >>>>>>> <mailto:r-390@mailman.qth.net>; >>>>>>> Larry Haney <larry41...@gmail.com <mailto:larry41...@gmail.com> >>>>>>> <mailto:larry41...@gmail.com>> Objet : Re: [R-390] Official specs >>>>>>> >>>>>>> Hi >>>>>>> >>>>>>> The very basic issue here turns that into a “that depends” answer: >>>>>>> >>>>>>> If you are playing with a Spice model, and starting from the voltage on >>>>>>> your ideal source, you get one answer. >>>>>>> >>>>>>> If you are working at RF and using a signal generator (and doing things >>>>>>> properly) you get a very different answer. >>>>>>> >>>>>>> The convention on an RF source is that the “starting voltage” is >>>>>>> measured with the correct termination in place. >>>>>>> >>>>>>> Since we’re talking about RF …. that’s how it would be done. >>>>>>> >>>>>>> Bob >>>>>>> >>>>>>>> On Oct 23, 2024, at 10:39 AM, Ing. Giovanni Becattini via R-390 >>>>>>>> <r-390@mailman.qth.net <mailto:r-390@mailman.qth.net> >>>>>>>> <mailto:r-390@mailman.qth.net>> wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> I find this topic very intriguing, so I cannot help but return to this >>>>>>>> discussion. >>>>>>>> >>>>>>>> As I told you, I don't consider myself an RF expert or simply a 390 >>>>>>>> expert, but I have had to solve complex engineering problems many >>>>>>>> times in my life. So I think we should first create a mathematical >>>>>>>> model that is as simple as possible, i.e. without taking into account >>>>>>>> the frequency effect. Once the model works, we can try to make it more >>>>>>>> real with the right corrections. >>>>>>>> >>>>>>>> So I would like to ask a question to see if we are on the same page: >>>>>>>> Do you agree that if the R-390A were a perfect 125 ohm resistor and we >>>>>>>> were working at 1 kHz, the DA-121 would attenuate 5 dB in voltage and >>>>>>>> 8.98 in power? >>>>>>>> >>>>>>>> Greetings >>>>>>>> >>>>>>>> Gianni >>>>>>>> >>>>>>>>> Il giorno 23 ott 2024, alle ore 16:15, Larry Haney >>>>>>>>> <larry41...@gmail.com <mailto:larry41...@gmail.com> >>>>>>>>> <mailto:larry41...@gmail.com>> ha scritto: >>>>>>>>> >>>>>>>>> Jim, I read your referenced post a few times looking for the answer >>>>>>>>> we're all looking for, what the microvolt level is that is going >>>>>>>>> into the 390 for a given level going into the DA-121, but I couldn't >>>>>>>>> find it. All I read was a bunch of db numbers that don't make any >>>>>>>>> difference. We need to know about the uV levels. You can talk >>>>>>>>> about insertion losses all you want, but that does not tell us what >>>>>>>>> the uV level is that is going into the 390. >>>>>>>>> >>>>>>>>> I used my URM-25D to generate a 1 MegaHertz 50 uV signal into the >>>>>>>>> DA-121 and got 28 uV going into the 390 (that's a 44% reduction of >>>>>>>>> signal from the 25D as measured with my HP 400FL RMS RF AC >>>>>>>>> voltmeter). Nothing else matters. The calculation is very simple: >>>>>>>>> 50 - 28 = 22, 22 / 50 = .4444 or 44.44%. That means that 55.55% of >>>>>>>>> the signal from the SG is getting to the >>>>>>>>> 390. The accuracy of my 400FL is +/- 1%. All my signal measurements >>>>>>>>> were >>>>>>>>> in RF RMS volts measured with my HP 400FL. >>>>>>>>> >>>>>>>>> The ONLY DC measurements I made were to measure the resistances in >>>>>>>>> the >>>>>>>>> DA-121 and mine are a 70 ohm shunt and a 100 ohm in series. These >>>>>>>>> are close to the documented values of 68 ohms and 100 ohms. >>>>>>>>> >>>>>>>>> So, what uV level of signal do you MEASURE (not calculated or >>>>>>>>> theorized) going into the DA-121 and going into the 390. Let's keep >>>>>>>>> it simple and stick to *MICROVOLTS* because that is what the >>>>>>>>> sensitivity and signal to noise ratio measurements use, NOT db. >>>>>>>>> >>>>>>>>> By the way, since this test is all about the DA-121, you should be >>>>>>>>> using the documented resistor values in it for testing (68 and 100 >>>>>>>>> ohms). >>>>>>>>> >>>>>>>>> And contrary to what you said, my DC circuit calculations >>>>>>>>> (resistance and estimated signal loss) do agree with my RF >>>>>>>>> measurements. The resistance calculation is: 100 ohms / (100 + 125 >>>>>>>>> ohms) = .4444. That's a 44% loss. >>>>>>>>> To get the signal level at the 390, multiply the SG output by 56%. >>>>>>>>> And I did not calculate any db loss, the 5 db loss is what my 400FL >>>>>>>>> says it is. >>>>>>>>> >>>>>>>>> For anyone wanting to make their own DA-121, use what's documented >>>>>>>>> in it, a >>>>>>>>> 68 ohm shunt and 100 ohm series resistor. Otherwise you will get a >>>>>>>>> different answer from those that use a real DA-121. >>>>>>>>> >>>>>>>>> Regards, Larry >>>>>>>>> >>>>>>>>> On Tue, Oct 22, 2024 at 3:36 PM Jim Whartenby <old_ra...@aol.com >>>>>>>>> <mailto:old_ra...@aol.com> <mailto:old_ra...@aol.com>> wrote: >>>>>>>>> >>>>>>>>>> Larry >>>>>>>>>> >>>>>>>>>> I built a test fixture that is essentially two DA-121's connected >>>>>>>>>> back to back. Photos and drawing are enclosed. This does the >>>>>>>>>> conversion from 50 ohms to 125 ohms and then back to 50 ohms. I >>>>>>>>>> used 1% resistors to make the attenuator circuit with the values >>>>>>>>>> close to those found here: >>>>>>>>>> >>>>>>>>>> https://k7mem.com/Res_Attenuator.html >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> The closest I could come to the 64.18 ohms result from the >>>>>>>>>> attenuator calculator was 63.9 ohms. This is from the parallel >>>>>>>>>> combination of 3 each >>>>>>>>>> 237 ohm in parallel with a 1k, in parallel with a 499 ohm resistor. >>>>>>>>>> Five resistors in parallel, all 1% resistors. The result was 63.85 >>>>>>>>>> ohms, a 0.5% error. The sub for the 96.83 ohm resistor is a 100 >>>>>>>>>> ohm 1% resistor (3% >>>>>>>>>> error) and the sub for the R-390's 125 ohm impedance was a 121 ohm >>>>>>>>>> 1% resistor (3% error). This is still much better then the 5% >>>>>>>>>> resistors used in the original DA-121. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> For a test oscillator I used a Helper SM-1000 signal generator and >>>>>>>>>> measured the insertion loss with a Stoddart NM-25T frequency >>>>>>>>>> selective voltmeter. The insertion loss was measured at 10 MHz >>>>>>>>>> using two 4 foot BNC >>>>>>>>>> RG-58 coax cables from Pomona Electric. 4 foot of coax from the >>>>>>>>>> SM-1000 to the test fixture and another 4 feet from the test fixture >>>>>>>>>> to the NM-25T. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> The SG was set for a reading of 30 dB on the NM-25T signal strength >>>>>>>>>> meter when measuring a BNC through connection and then measured 11 >>>>>>>>>> dB when the >>>>>>>>>> test fixture was installed in place of the BNC through. The >>>>>>>>>> insertion >>>>>>>>>> loss for the test fixture is 19 dB. Dividing this by two since >>>>>>>>>> there are essentially two DA-121s back to back gives an insertion >>>>>>>>>> loss of about 9.5 dB for a single DA-121. This closely agrees with >>>>>>>>>> the attenuator calculator findings. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> So it seems that your DC circuit calculation do not agree with the >>>>>>>>>> RF measurements. Transmission lines behave differently then DC >>>>>>>>>> circuits. You calculate a 5 dB insertion loss, I measure a 9.5 dB >>>>>>>>>> insertion loss. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Here is an experiment that you can try. Insert a 50 ohm resistor >>>>>>>>>> in parallel with the 50 ohm coax. What do you think will happen? >>>>>>>>>> Perhaps nothing since the coax is 50 ohms and the resistor is also >>>>>>>>>> 50 ohms? In reality, the coax has reactive elements, parallel >>>>>>>>>> capacitance and series inductance that make up the coax impedance. >>>>>>>>>> Neither of which will dissipate the signal carried on the coax. >>>>>>>>>> The only losses are from the resistance of the conductors that make >>>>>>>>>> up the coax. Adding a parallel resistor will attenuate the signal >>>>>>>>>> to the receiver by 3 dB. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> If anyone on this list wants to make their own version of the >>>>>>>>>> DA-121, I can supply the resistor values I used for a token $2 plus >>>>>>>>>> postage. Just DM me with your address and if you want one or two >>>>>>>>>> resistor sets. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Regards, Jim >>>>>>>>>> >>>>>>>>>> Logic: Method used to arrive at the wrong conclusion, with >>>>>>>>>> confidence. >>>>>>>>>> Murphy >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Friday, October 18, 2024 at 05:36:08 AM CDT, Larry Haney < >>>>>>>>>> larry41...@gmail.com <mailto:larry41...@gmail.com> >>>>>>>>>> <mailto:larry41...@gmail.com>> wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Hi Jim, I just checked and I only have 1 da-121. As for insertion >>>>>>>>>> loss, my coax is very short and the connections are very good so >>>>>>>>>> the loss there would not be possible for me to measure. Now for >>>>>>>>>> the insertion loss due to impedance mismatch (due to resistance >>>>>>>>>> variations) would also not be possible for me to measure, as I >>>>>>>>>> don't have the equipment required for that. But, because the 3 >>>>>>>>>> resistors in the circuit are very close to the required values for >>>>>>>>>> a perfect >>>>>>>>>> 50 ohm match to the sig gen, I am sure that the insertion loss due >>>>>>>>>> to that very slight impedance mismatch is extremely small. I have >>>>>>>>>> no way to measure that loss as I don't have the 3 exact value >>>>>>>>>> resistors to compare it to. I could calculate it, but I believe >>>>>>>>>> that would be a waste of time without being able to measure it. >>>>>>>>>> >>>>>>>>>> After all the input you have given me and the research just done, >>>>>>>>>> I'm satisfied with my current measurements and calculations (IE: >>>>>>>>>> the output voltage of the da-121 is 56% of the input voltage when >>>>>>>>>> the load is >>>>>>>>>> 125 ohms). >>>>>>>>>> >>>>>>>>>> My biggest concern about making snr measurements is for those folks >>>>>>>>>> that don't have a recently calibrated sig gen or calibrated rms AC >>>>>>>>>> voltmeter to verify their readings with. >>>>>>>>>> >>>>>>>>>> Regards, Larry >>>>>>>>>> >>>>>>>>>> On Thu, Oct 17, 2024 at 1:55 PM Jim Whartenby <old_ra...@aol.com >>>>>>>>>> <mailto:old_ra...@aol.com> <mailto:old_ra...@aol.com>> wrote: >>>>>>>>>> >>>>>>>>>> Larry >>>>>>>>>> No, just one SG and one 125 ohm load. You should be able to >>>>>>>>>> determine the total loss through two DA-121 attenuators connected >>>>>>>>>> back to back with an o'scope and then divide the loss by two to >>>>>>>>>> solve for the insertion loss. >>>>>>>>>> Jim >>>>>>>>>> Logic: Method used to arrive at the wrong conclusion, with >>>>>>>>>> confidence. >>>>>>>>>> Murphy >>>>>>>>>> >>>>>>>>>> >>>>>>>>> ______________________________________________________________ >>>>>>>>> R-390 mailing list >>>>>>>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>>>>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>>>>>> Post: mailto:R-390@mailman.qth.net >>>>>>>>> >>>>>>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>>>>>> <http://www.qsl.net/> Please help support this >>>>>>>>> email list: http://www.qsl.net/donate.html >>>> >>>>>>>> >>>>>>>> ______________________________________________________________ >>>>>>>> R-390 mailing list >>>>>>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>>>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>>>>> Post: mailto:R-390@mailman.qth.net >>>>>>>> >>>>>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>>>>> <http://www.qsl.net/> Please help support this >>>>>>>> email >>>>>>>> list: http://www.qsl.net/donate.html >>>>>>> >>>>>>> ______________________________________________________________ >>>>>>> R-390 mailing list >>>>>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>>>> Post: mailto:R-390@mailman.qth.net >>>>>>> >>>>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>>>> <http://www.qsl.net/> Please help support this email >>>>>>> list: http://www.qsl.net/donate.html >>>>>>> >>>>>> >>>>>> ______________________________________________________________ >>>>>> R-390 mailing list >>>>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>>> Post: mailto:R-390@mailman.qth.net >>>>>> >>>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>>> <http://www.qsl.net/> >>>>>> Please help support this email list: http://www.qsl.net/donate.html >>>>> ______________________________________________________________ >>>>> R-390 mailing list >>>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>> Post: mailto:R-390@mailman.qth.net >>>>> >>>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>>> <http://www.qsl.net/> >>>>> Please help support this email list: http://www.qsl.net/donate.html >>>> >>>> ______________________________________________________________ >>>> R-390 mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/r-390 >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:R-390@mailman.qth.net >>>> >>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>> <http://www.qsl.net/> >>>> Please help support this email list: http://www.qsl.net/donate.html >>> >> >> ______________________________________________________________ >> R-390 mailing list >> Home: http://mailman.qth.net/mailman/listinfo/r-390 >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:R-390@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:R-390@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
