Jedi - RX problem - can I swap RF board with similar model?
Posted: Wed Mar 05, 2008 2:42 pm
I have just acquired an MT2100 UHF radio. Details are as follows:
Type : PJ502D
Model : H01RDD9PW1BN
The MT2100 seems to work OK on TX but I think there is a problem with the RX side.
When you open the SQ (to get white noise), instead of a steady "hiss" , there is an unstable burbling noise. BUT when you inject a weak signal for a brief second , the RX side then gives the usual white noise. BUT if you TX for a brief second , the unstable RX burbling noise is back. Its definately not local QRM etc - you might also not notice the problem if the SQ was just kept close - but if you are monitoring a carrier and press the PTT , when you dekey , there is a very brief "burble" - if there was no test carrier and the SQ open , the burbling would be there all the time.
I think I had a similar problem with a VHF MT2000 but it was also 5KHz off freq - at the time I think the Batlabs experts thought it was probably a bad IF IC (which is difficult to replace).
Any thoughts on the MT2100 problem?
I have a couple of spare GP900 / GP1200/ MTS1200 RF boards. Can I just replace the RF board from the MT2100 with , say , a GP900 RF board? Will I need to realign the "replacement" RF board when it is installed into the MT2100 - or is the alignment info held on the RF board rather than the control board??
Thanks
Type : PJ502D
Model : H01RDD9PW1BN
The MT2100 seems to work OK on TX but I think there is a problem with the RX side.
When you open the SQ (to get white noise), instead of a steady "hiss" , there is an unstable burbling noise. BUT when you inject a weak signal for a brief second , the RX side then gives the usual white noise. BUT if you TX for a brief second , the unstable RX burbling noise is back. Its definately not local QRM etc - you might also not notice the problem if the SQ was just kept close - but if you are monitoring a carrier and press the PTT , when you dekey , there is a very brief "burble" - if there was no test carrier and the SQ open , the burbling would be there all the time.
I think I had a similar problem with a VHF MT2000 but it was also 5KHz off freq - at the time I think the Batlabs experts thought it was probably a bad IF IC (which is difficult to replace).
Any thoughts on the MT2100 problem?
I have a couple of spare GP900 / GP1200/ MTS1200 RF boards. Can I just replace the RF board from the MT2100 with , say , a GP900 RF board? Will I need to realign the "replacement" RF board when it is installed into the MT2100 - or is the alignment info held on the RF board rather than the control board??
Thanks