0000067: RFI in autocorr AX & AY in 1 band lineobservations (LBand)

Issue History
Date Modified	Username	Field	Change
05-09-08 09:42	Jurjen Sluman	New Issue
08-09-08 11:07	Jurjen Sluman	Note Added: 0000078
08-09-08 11:08	Jurjen Sluman	Category	0.unknown/unspecified => front-end
08-09-08 11:09	Jurjen Sluman	Project	submission => MFFE
08-09-08 11:09	Jurjen Sluman	MFFE	=> 00
08-09-08 11:09	Jurjen Sluman	RT	=> 0
08-09-08 11:09	Jurjen Sluman	Assigned To	=> Harm-Jan Stiepel
08-09-08 11:09	Jurjen Sluman	Status	new => assigned
08-09-08 11:09	Jurjen Sluman	Category	front-end => 0.unknown/unspecified
24-09-08 12:00	Hans van der Marel	Project	MFFE => RFI
24-09-08 12:03	Hans van der Marel	MFFE-band	=> 21cm, L-band
24-09-08 12:03	Hans van der Marel	RT	0 => A
24-09-08 12:03	Hans van der Marel	character of RFI	=> constant
24-09-08 12:03	Hans van der Marel	Category	0.unknown/unspecified => internal
24-09-08 12:12	Hans van der Marel	Note Added: 0000092
25-09-08 08:05	Bert Woestenburg	Description Updated
25-09-08 08:05	Bert Woestenburg	Additional Information Updated
03-10-08 09:33	Jurjen Sluman	Note Added: 0000094
06-10-08 14:37	Bert Woestenburg	Note Added: 0000095
06-10-08 14:39	Bert Woestenburg	Assigned To	Harm-Jan Stiepel => Bert Woestenburg
06-10-08 14:40	Bert Woestenburg	Assigned To	Bert Woestenburg => Harm-Jan Stiepel
07-10-08 06:41	Bert Woestenburg	MFFE-band	21cm, L-band => UHF-high, 21cm, L-band
08-10-08 09:03	Yuan Tang	Additional Information Updated
08-10-08 09:04	Yuan Tang	Status	assigned => testing
08-10-08 10:02	Hans van der Marel	Project	RFI => IVC/ADC
08-10-08 10:03	Hans van der Marel	Status	testing => assigned
08-10-08 10:03	Hans van der Marel	Assigned To	Harm-Jan Stiepel => Hans Weggemans
29-10-08 06:33	Hans Weggemans	Note Added: 0000100
31-10-08 10:56	Yuan Tang	sub-band	=> 0
31-10-08 10:56	Yuan Tang	Category	internal => 0.unknown/unspecified
21-11-08 08:51	Yuan Tang	Note Added: 0000110
01-12-08 09:37	Jurjen Sluman	Status	assigned => information
03-12-08 11:18	Bert Woestenburg	Note Added: 0000114
11-12-08 15:31	Yuan Tang	Note Added: 0000118
13-01-09 08:11	Jurjen Sluman	Note Added: 0000121
13-01-09 08:11	Jurjen Sluman	Status	information => resolved
22-06-11 07:14	Juergen Morawietz	Status	resolved => closed

Notes
(0000078) Jurjen Sluman 08-09-08 11:07	MFFE will be removed

(0000092) Hans van der Marel 24-09-08 12:12	The reported RFI is only visible during line observations at 10 MHz BW. The frequency is not always the same, e.g. for an MFFE frequency of 1418 MHz the RFI (CW) has been seen at 1417.64, 1417.74, 1417.76, 1417.85... and for an MFFE freq of 1420 MHz at has been seen at 1419.76 and 1419.74. It can be concluded that the RFI is not locked to the LO. Something is oscillating. It looks like it is moving with the MFFE frequency, so there is probably something in the back-end and because it seems to be BW related, it might be a filter unit of the IVC.

(0000094) Jurjen Sluman 03-10-08 09:33	This problem is also seen in a 1 bands line observation in with a freq. in the UHFH band. (10804812..10804813)

(0000095) Bert Woestenburg 06-10-08 14:37	The problem is not related to the MFFE, but most likely IVC. Based on remarks of Hans van der Marel now assigned to Hans Weggemans

(0000100) Hans Weggemans 29-10-08 06:33	27-10-2008 to trace the RFI at AX,Ay(at 21cm with BW=10), the preselector board 2 has been swapped with preselector board 0.

(0000110) Yuan Tang 21-11-08 08:51	21-11-2008 This problem is still there, see 10805789-10805791.

(0000114) Bert Woestenburg 03-12-08 11:18	The RFI has disappeared in recent observations after work on the system by Albert Bos, but it is unclear what caused this change. Status set to "Information" on 1-12-08.

(0000118) Yuan Tang 11-12-08 15:31	20081211: The problem appears again after installing the new version of DZB at Dec.09.

(0000121) Jurjen Sluman 13-01-09 08:10	We have not seen this effect for a long term.

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