Re: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio
There's a discussion of flipping over the Micor receiver AFC diodes on the web page at <http://www.repeater-builder.com/rbtip/micoruhfmobile.html>. Mike At 07:00 AM 11/29/06, you wrote: > >Wouldn't hurt ... but if you want the AFC to work properly, you will need > to change the direction of the discriminator diodes. > >Neil - > > >- Original Message - >From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> >Date: Tuesday, November 28, 2006 7:31 am >Subject: Re: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio > > > Should the same high-side injection be requested when ordering 440- > > 450 MHz crystals for a MICOR channel element? So far, everything > > has tuned up very well just having ICM make new crystals according > > to the standard MICOR receiver formula, and I always send in the > > channel elements to be completely temperature compensated, etc. > > while I'm at it. But I've wondered if future orders should also > > request that they be ordered with high-side injection? > > > > LJ > > > > > > ----Original Message----- > > >From: k6jsi <[EMAIL PROTECTED]> > > >Sent: Nov 27, 2006 9:00 PM > > >To: Repeater-Builder@yahoogroups.com > > >Subject: [Repeater-Builder] Re: spur from UHF MASTR II mobile - > > link radio > > > > > >--- In Repeater-Builder@yahoogroups.com, "Don Kupferschmidt" > > ><[EMAIL PROTECTED]> wrote: > > >> > > >> Nate, > > >> > > >> I'm wondering if you can point me to a link that would further > > >explain lo / > > >> hi injection. Hate to admit, but I'm not all that familiar > > about > > >the > > >> subject, especially in repeater operation. > > >> > > >> TIA, > > >> > > >> Don, KD9PT > > >> > > >> > > > (Snip) > > > > > >Hi Don, > > > > > >The normal MASTR II receiver uses a low-side Local Oscillator > > >injection for their mixer. The IF is 11.2 MHz, so you deduct > > 11.2 > > >MHz from the operating frequency. The normal operating frequency > > >for the 88 series MASTR II radios is 450 to 470, so the LO (Local > > >Oscillator) is engineered to run between 438.8 and 458.8 MHz (450 ? > > >11.2 = 438.8; and 470 ?11.2 = 458.8). > > > > > >When we in the amateur radio service order a low-side injection > > >crystal, we are essentially asking the LO to operate between > > 428.8 > > >and 438.8 MHz, worst case being 10 MHz below the engineered > > >operating frequency range (440 ?11.2 = 428.8, and 450 ?11.2 = > > >438.8) This is stretching the original design of the local > > >oscillator 10 MHz beyond the design parameters. > > > > > >If we order high-side injection crystals, we add 11.2 MHz to our > > >operating frequency, rather than subtract it. So the LO will > > runs > > >between 451.2 and 461.2 MHz (440 + 11.2 = 451.2, and 450 +11.2 = > > >462.2). > > > > > >If you are operating in an area of the country where you run low- > > in, > > >high-out split repeaters, your receivers will operate between 440 > > >and 445 MHz, and the highest possible LO frequency will be 456.2 > > MHz > > >(445 + 11.2 = 456.2), or right in the sweet spot for the LO range > > >(438.8 and 458.8). > > > > > >If you are operating in an area of the country where you run high- > > >in, low-out split repeaters, and your receiver will operate > > between > > >445 and 450 MHz, and the highest possible LO frequency will be > > 450 + > > >11.2 = 462.2, or only 3.4 MHz higher than the designed frequency > > of > > >the LO. > > > > > >The cross-over frequency seems to be 448.300 MHz, which is 1.7 > > MHz > > >higher at a high-side injection than designed, and a low-side > > >injection is 1.7 MHz lower than designed Local Oscillator. > > > > > >So, maybe a good rule of thumb would be to order high-side > > injection > > >on operating frequencies below 448.300, and low-side injection on > > >receive frequencies above 448.300. That way, the worst case > > >scenario is your being either 1.7 MHz higher or lower than the > > >original engineered design on the local oscillator. > > > > > >You can do the same math for high-band radios. Same IF. > > > > > >Hope that helps. > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > >Yahoo! Groups Links > > >
Re: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio
Wouldn't hurt ... but if you want the AFC to work properly, you will need to change the direction of the discriminator diodes. Neil - - Original Message - From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> Date: Tuesday, November 28, 2006 7:31 am Subject: Re: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio > Should the same high-side injection be requested when ordering 440- > 450 MHz crystals for a MICOR channel element? So far, everything > has tuned up very well just having ICM make new crystals according > to the standard MICOR receiver formula, and I always send in the > channel elements to be completely temperature compensated, etc. > while I'm at it. But I've wondered if future orders should also > request that they be ordered with high-side injection? > > LJ > > > Original Message- > >From: k6jsi <[EMAIL PROTECTED]> > >Sent: Nov 27, 2006 9:00 PM > >To: Repeater-Builder@yahoogroups.com > >Subject: [Repeater-Builder] Re: spur from UHF MASTR II mobile - > link radio > > > >--- In Repeater-Builder@yahoogroups.com, "Don Kupferschmidt" > ><[EMAIL PROTECTED]> wrote: > >> > >> Nate, > >> > >> I'm wondering if you can point me to a link that would further > >explain lo / > >> hi injection. Hate to admit, but I'm not all that familiar > about > >the > >> subject, especially in repeater operation. > >> > >> TIA, > >> > >> Don, KD9PT > >> > >> > > (Snip) > > > >Hi Don, > > > >The normal MASTR II receiver uses a low-side Local Oscillator > >injection for their mixer. The IF is 11.2 MHz, so you deduct > 11.2 > >MHz from the operating frequency. The normal operating frequency > >for the 88 series MASTR II radios is 450 to 470, so the LO (Local > >Oscillator) is engineered to run between 438.8 and 458.8 MHz (450 ? > >11.2 = 438.8; and 470 ?11.2 = 458.8). > > > >When we in the amateur radio service order a low-side injection > >crystal, we are essentially asking the LO to operate between > 428.8 > >and 438.8 MHz, worst case being 10 MHz below the engineered > >operating frequency range (440 ?11.2 = 428.8, and 450 ?11.2 = > >438.8) This is stretching the original design of the local > >oscillator 10 MHz beyond the design parameters. > > > >If we order high-side injection crystals, we add 11.2 MHz to our > >operating frequency, rather than subtract it. So the LO will > runs > >between 451.2 and 461.2 MHz (440 + 11.2 = 451.2, and 450 +11.2 = > >462.2). > > > >If you are operating in an area of the country where you run low- > in, > >high-out split repeaters, your receivers will operate between 440 > >and 445 MHz, and the highest possible LO frequency will be 456.2 > MHz > >(445 + 11.2 = 456.2), or right in the sweet spot for the LO range > >(438.8 and 458.8). > > > >If you are operating in an area of the country where you run high- > >in, low-out split repeaters, and your receiver will operate > between > >445 and 450 MHz, and the highest possible LO frequency will be > 450 + > >11.2 = 462.2, or only 3.4 MHz higher than the designed frequency > of > >the LO. > > > >The cross-over frequency seems to be 448.300 MHz, which is 1.7 > MHz > >higher at a high-side injection than designed, and a low-side > >injection is 1.7 MHz lower than designed Local Oscillator. > > > >So, maybe a good rule of thumb would be to order high-side > injection > >on operating frequencies below 448.300, and low-side injection on > >receive frequencies above 448.300. That way, the worst case > >scenario is your being either 1.7 MHz higher or lower than the > >original engineered design on the local oscillator. > > > >You can do the same math for high-band radios. Same IF. > > > >Hope that helps. > > > > > > > > > > > Yahoo! Groups Links > > > >
Re: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio
Should the same high-side injection be requested when ordering 440-450 MHz crystals for a MICOR channel element? So far, everything has tuned up very well just having ICM make new crystals according to the standard MICOR receiver formula, and I always send in the channel elements to be completely temperature compensated, etc. while I'm at it. But I've wondered if future orders should also request that they be ordered with high-side injection? LJ Original Message- >From: k6jsi <[EMAIL PROTECTED]> >Sent: Nov 27, 2006 9:00 PM >To: Repeater-Builder@yahoogroups.com >Subject: [Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio > >--- In Repeater-Builder@yahoogroups.com, "Don Kupferschmidt" ><[EMAIL PROTECTED]> wrote: >> >> Nate, >> >> I'm wondering if you can point me to a link that would further >explain lo / >> hi injection. Hate to admit, but I'm not all that familiar about >the >> subject, especially in repeater operation. >> >> TIA, >> >> Don, KD9PT >> >> > (Snip) > >Hi Don, > >The normal MASTR II receiver uses a low-side Local Oscillator >injection for their mixer. The IF is 11.2 MHz, so you deduct 11.2 >MHz from the operating frequency. The normal operating frequency >for the 88 series MASTR II radios is 450 to 470, so the LO (Local >Oscillator) is engineered to run between 438.8 and 458.8 MHz (450 � >11.2 = 438.8; and 470 �11.2 = 458.8). > >When we in the amateur radio service order a low-side injection >crystal, we are essentially asking the LO to operate between 428.8 >and 438.8 MHz, worst case being 10 MHz below the engineered >operating frequency range (440 �11.2 = 428.8, and 450 �11.2 = >438.8) This is stretching the original design of the local >oscillator 10 MHz beyond the design parameters. > >If we order high-side injection crystals, we add 11.2 MHz to our >operating frequency, rather than subtract it. So the LO will runs >between 451.2 and 461.2 MHz (440 + 11.2 = 451.2, and 450 +11.2 = >462.2). > >If you are operating in an area of the country where you run low-in, >high-out split repeaters, your receivers will operate between 440 >and 445 MHz, and the highest possible LO frequency will be 456.2 MHz >(445 + 11.2 = 456.2), or right in the sweet spot for the LO range >(438.8 and 458.8). > >If you are operating in an area of the country where you run high- >in, low-out split repeaters, and your receiver will operate between >445 and 450 MHz, and the highest possible LO frequency will be 450 + >11.2 = 462.2, or only 3.4 MHz higher than the designed frequency of >the LO. > >The cross-over frequency seems to be 448.300 MHz, which is 1.7 MHz >higher at a high-side injection than designed, and a low-side >injection is 1.7 MHz lower than designed Local Oscillator. > >So, maybe a good rule of thumb would be to order high-side injection >on operating frequencies below 448.300, and low-side injection on >receive frequencies above 448.300. That way, the worst case >scenario is your being either 1.7 MHz higher or lower than the >original engineered design on the local oscillator. > >You can do the same math for high-band radios. Same IF. > >Hope that helps. > >
[Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio
--- In Repeater-Builder@yahoogroups.com, "Don Kupferschmidt" <[EMAIL PROTECTED]> wrote: > > Nate, > > I'm wondering if you can point me to a link that would further explain lo / > hi injection. Hate to admit, but I'm not all that familiar about the > subject, especially in repeater operation. > > TIA, > > Don, KD9PT > > (Snip) Hi Don, The normal MASTR II receiver uses a low-side Local Oscillator injection for their mixer. The IF is 11.2 MHz, so you deduct 11.2 MHz from the operating frequency. The normal operating frequency for the 88 series MASTR II radios is 450 to 470, so the LO (Local Oscillator) is engineered to run between 438.8 and 458.8 MHz (450 11.2 = 438.8; and 470 11.2 = 458.8). When we in the amateur radio service order a low-side injection crystal, we are essentially asking the LO to operate between 428.8 and 438.8 MHz, worst case being 10 MHz below the engineered operating frequency range (440 11.2 = 428.8, and 450 11.2 = 438.8) This is stretching the original design of the local oscillator 10 MHz beyond the design parameters. If we order high-side injection crystals, we add 11.2 MHz to our operating frequency, rather than subtract it. So the LO will runs between 451.2 and 461.2 MHz (440 + 11.2 = 451.2, and 450 +11.2 = 462.2). If you are operating in an area of the country where you run low-in, high-out split repeaters, your receivers will operate between 440 and 445 MHz, and the highest possible LO frequency will be 456.2 MHz (445 + 11.2 = 456.2), or right in the sweet spot for the LO range (438.8 and 458.8). If you are operating in an area of the country where you run high- in, low-out split repeaters, and your receiver will operate between 445 and 450 MHz, and the highest possible LO frequency will be 450 + 11.2 = 462.2, or only 3.4 MHz higher than the designed frequency of the LO. The cross-over frequency seems to be 448.300 MHz, which is 1.7 MHz higher at a high-side injection than designed, and a low-side injection is 1.7 MHz lower than designed Local Oscillator. So, maybe a good rule of thumb would be to order high-side injection on operating frequencies below 448.300, and low-side injection on receive frequencies above 448.300. That way, the worst case scenario is your being either 1.7 MHz higher or lower than the original engineered design on the local oscillator. You can do the same math for high-band radios. Same IF. Hope that helps.
[Repeater-Builder] Re: spur from UHF MASTR II mobile - link radio
--- In Repeater-Builder@yahoogroups.com, "Don Kupferschmidt" <[EMAIL PROTECTED]> wrote: > > Nate, > > I'm wondering if you can point me to a link that would further explain lo / > hi injection. Hate to admit, but I'm not all that familiar about the > subject, especially in repeater operation. > > TIA, > > Don, KD9PT > > > - Original Message - > From: "Nate Duehr" <[EMAIL PROTECTED]> > To: > Sent: Monday, November 27, 2006 6:45 PM > Subject: Re: [Repeater-Builder] spur from UHF MASTR II mobile - link radio > > > > FHS wrote: > >> Users of MII mobiles as repeaters and/or base stations: You should > >> expect interference when you cut corners to save a buck and use a mobile > >> for a repeater. The mobile has no shielding to prevent RF entry or exit, > >> none of the leads are in/out of the Rx and Tx are bypassed as in the MII > >> stations! *Mobile sets were never designed for this purpose.* If you put > >> a mobile on the air as a station and do not receive or give interference > >> to others, consider yourself lucky. > >> Fred W5VAY > > > > Fred missed that this isn't a repeater. But thanks for the reminder Fred. > > > > I agree with you on not using mobiles most of the time. > > > > For everyone else... I'm sitting here slapping my forehead and saying, > > "Duh". > > > > I was (for some unknown reason) trying to do external mix math on the > > numbers instead of simply subtracting the IF and then dividing... what a > > maon. > > > > Thanks for the (rather obvious now that I see it) help, all. > > > > Guess I'll try two things... put the crystals in a station and perhaps > > with a little better shielding I can lower the effect for now of the mix > > in the house... short-term, and then order up the high-side injection > > crystals for the rig and retune when they arrive... > > > > Nate WY0X > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > !DSPAM:1016,456b8b8217055802679531! > > > > >
