MPD 900 mhx
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MPD 900 mhx
Why go throw all that when you can just get yourself an MP-A 900 mhz and use the hamflash then you have nothing you worry about with hardware.
Cuz you can pick up an old still working 800MHz MPD for a couple of bucks and then like I said add new dielectric bandpass filters for about 12 dollars each and then a new power module for about 60 bucks and the vco modification and your done. Some people have access to the MPD for a few bucks wheras they can't get their hands on an 900 Mhz MPA or MTL for under a couple hundred bucks if you can even find them anymore, and the MPD has much better isolation from the controller board to the RF board than the MPA ever did, the MPD has better efficiency than the MPA rf section, the MPD VCO is easier to move to the 902-928 band than even the original stock MPA 900 rf sections VCO was which by the way also requires cutting into the VCO unless you have a large sample of TMX series VCOs to try swapping to see if they'll work in the 900 ham band. Some MPAs will go there with minimal mods but out of several that I've hamflashed 90 % of them took more work than MPD 800s did.
Also with the 900 MHZ hamflash you need to pull the TCXO off frequency if you want to do the sliver channels at 12.5 Khz spacings IE like for instance if you want to program in 927.4875 Mhz with the hamflash you need to offset the tcxo low by 12.5 Khz and still program in a frequency of 927.500 since the hamflash programming only alows 6 digits and the radio when hamflashed will only alow VCO step changes in 25 KHz incrememts even though if you are in VFO mode the display will indicate 5 KHZ steps, the vco actual does not change until 5 steps have occured IE 25 KHz changes.
The MPD will do splinter channels like 927.4875 and 927.600 the national simplex frequency in 12.5 Khz increments, you cannot do this in a Hamflashed MPA it is either the splinter channels like 927.4875 in 25 Khz increments or 927.500 for instance in 25 Khz increments but not both with the MPA when hamflashed.
Also the hamflash does not support DCS tones which are becoming popular in the 902 band. Also there are some VCO voltage Regulator mods needed in an MPA to allow operation below 905 MHz without terrible hum in the tx audio along with shielding of the front assy. flex to keep rf out of the audio circuits during txing not to mention that even some of the stock MPA 900s require changing the Dielectric filters to get below 927 Mhz if needed. Aside from that if you don't need DCS or full band coverage and can get by with either splinter channels or standard channels but not both then the MPA is indeed nice, I have both radios and enjom each and have converted numerous MPDs, MPAs and MTLs to the 902-928 band and have uses for all of them depending on where I am using the radios at.
BTW the same applies for a 900 MHz GENET MTL, especially if it has the DTMF front, by reconnecting 2 PWB wiresthat were cut in the factory on the keypad section it can be hamflashed and then with an added escution and new keypad to gain access to the top 4 keys that an MPA has and the genet MTL doesn't have, you basically now have an MPA and the MTLs usually go for a lower price than an 900 Mpa will.
Mike
Also with the 900 MHZ hamflash you need to pull the TCXO off frequency if you want to do the sliver channels at 12.5 Khz spacings IE like for instance if you want to program in 927.4875 Mhz with the hamflash you need to offset the tcxo low by 12.5 Khz and still program in a frequency of 927.500 since the hamflash programming only alows 6 digits and the radio when hamflashed will only alow VCO step changes in 25 KHz incrememts even though if you are in VFO mode the display will indicate 5 KHZ steps, the vco actual does not change until 5 steps have occured IE 25 KHz changes.
The MPD will do splinter channels like 927.4875 and 927.600 the national simplex frequency in 12.5 Khz increments, you cannot do this in a Hamflashed MPA it is either the splinter channels like 927.4875 in 25 Khz increments or 927.500 for instance in 25 Khz increments but not both with the MPA when hamflashed.
Also the hamflash does not support DCS tones which are becoming popular in the 902 band. Also there are some VCO voltage Regulator mods needed in an MPA to allow operation below 905 MHz without terrible hum in the tx audio along with shielding of the front assy. flex to keep rf out of the audio circuits during txing not to mention that even some of the stock MPA 900s require changing the Dielectric filters to get below 927 Mhz if needed. Aside from that if you don't need DCS or full band coverage and can get by with either splinter channels or standard channels but not both then the MPA is indeed nice, I have both radios and enjom each and have converted numerous MPDs, MPAs and MTLs to the 902-928 band and have uses for all of them depending on where I am using the radios at.
BTW the same applies for a 900 MHz GENET MTL, especially if it has the DTMF front, by reconnecting 2 PWB wiresthat were cut in the factory on the keypad section it can be hamflashed and then with an added escution and new keypad to gain access to the top 4 keys that an MPA has and the genet MTL doesn't have, you basically now have an MPA and the MTLs usually go for a lower price than an 900 Mpa will.
Mike
MPD 900 mhx
I don't konw about all that I've hamflashed 5 900 mhz MP-A over the last year here in Denver had to do nothing else and they work great but they I have the last version of hamflash which was redone in 2000 only a few people have it and it returns the rf deck just fine they fixed a lot of bugs in the last one. But you will never find it unless you know someone that wants to give it up. As to the MPD it had it's type ecpt pulled by the FCC in the yr 1999 because it will not meet specs of any kind it also drops audio a lot. As to the rf deck a lot of the MP-A radio built after 92 has the real sheld over the front side.
Will the 2000 hamflash allow splinter and standard channels, the latest version that I have was turned out around 1998 which was great for VHF. UHF and 220MHz but like I said it required more work on 900 Mhz.
Also does the 2000 hamflash correctly display the 900 frequencies in the VFO mode ? That is if it steps in 5KHz increments on the display is the radio actually channeling in 5khz steps ETC ?
Most of the MPAs and MTL I converted were piece part radiosthat didn't have front controller sections and they all required considerable Modifications done to them from the service manuals to bring them up to date, in fact I haven't found any that were pre 1992 according to the board modification rev letters.
I wouldn't mind getting my hands on some newer 900 MPAs to convert over if you know of a source aside from E-bay.
Mike
Also does the 2000 hamflash correctly display the 900 frequencies in the VFO mode ? That is if it steps in 5KHz increments on the display is the radio actually channeling in 5khz steps ETC ?
Most of the MPAs and MTL I converted were piece part radiosthat didn't have front controller sections and they all required considerable Modifications done to them from the service manuals to bring them up to date, in fact I haven't found any that were pre 1992 according to the board modification rev letters.
I wouldn't mind getting my hands on some newer 900 MPAs to convert over if you know of a source aside from E-bay.
Mike
MPD 900 mhx
the newer hamflash covers everything fron 5kz and up. Also I have lots of newer edacs borad that where made all the way up to 99 when the last MP-A was made.